• Journal of Plant Biotechnology
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• v.33 no.2
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• pp.147-152
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• 2006

This work was carried out to establish adventitious root culture system in three Panax species (wild-grown P. ginseng, P. quinquefolium, and P. japonicum) to analyze their ginsenoside productivity. Adventitious roots were induced directly from segments of seedlings after cultured on MS(Murashige andSkoog 1962) solid medium containing 3.0 mg/l IBA. Omission of $NH_4NO_3$ from the medium greatly enhanced both the frequency of adventitious root formation and number of roots per explants in all the three Panax species. However, elongation of post-induced adventitious roots was enhanced on medium with $NH_4NO_3$. Two-step culture protocol: $NH_4NO_3$-free medium for first two weeks of culture, followed by $NH_4NO_3$ containing medium for further 4 weeks, greatly enhanced the fresh weight increase of adventitious roots in all the three ginseng species. The fresh weight of adventitious roots was high in P. quinquefolium and low in P. ginseng, followed by P. japonioum regardless of the composition of medium. Pattern and content of ginsenosides in adventitious roots differed among the three Panax species. Total ginsenoside content of adventitious roots in P. quinquefolium, P. ginseng, and p. japonicum was 8.03, 15.7 and 1.2 mg/g dry weight, respectively. Among the three speices, adventitious roots in P. quinquefolium produced hig-hamount of ginsenosides. The pattern of ginsenoside fractions between P. ginseng and P. quinquefolium was similar but the amount of ginsenoside differed between the two, While, in P japonicum, total ginsenoside content was very low and some ginsenosides such as ginsenoside Rb2 and Rf were not detected. Conclusively, we demonstrate that same culture condition was required for induction and elongation of adventitious roots of three ginseng species but growth of adventitious roots and their ginsenoside production were different among them.

• Journal of the Korean Mathematical Society
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• v.57 no.1
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• pp.215-247
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• 2020

In this paper, we deal with a two-species chemotaxis-Stokes system with Lotka-Volterra competitive kinetics under homogeneous Neumann boundary conditions in a general three-dimensional bounded domain with smooth boundary. Under appropriate regularity assumptions on the initial data, by some L^p-estimate techniques, we show that the system possesses at least one global and bounded weak solution, in addition to discussing the asymptotic behavior of the solutions. Our results generalizes and improves partial previously known ones.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.169-178
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• 1999

The natural regeneration pattern was evaluated for 11 useful hardwood species in the natural deciduous forest where three different silvicultural practices (two-storied system, shelterwood system, and selection system) were applied and passed by three growing seasons. The study forest was presently dominated by Quercus mongolica in the upper canopy. However, since the analysis indicated that the number of regenerated seedlings of Acer mono and Fraxinus rhynchophylla was fairly abundant enough, these two species were anticipated to have the possibility to be among dominant species along with Quercus mongolica. The results of seedling occurrence after regenerating cutting showed that the number of seedlings was estimated for 3,145/ha(10 times of overstory) in the two-storied system, 6,885/ha(9 times of overstory) in the shelterwood system, and 2,275/ha(4 times of overstory) in the selection system. The estimation was varied by species, and the number of stump sprout was more abundant. The proportion of seedlings was high in 60~80% of overstory density and 60~70% of understory coverage, and high in the site of less than $25^{\circ}$ of slope and from southwest to northwest of aspect. These results were still varied by species. Stump diameter and height had little influence on the occurrence of sprout.

• Biomedical Science Letters
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• v.26 no.3
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• pp.217-225
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• 2020

Scuttle fly which moves abruptly after standing for a while and stop suddenly to rush off again, is a fly species in the Phoridae family. This species like rotten organic materials and it is known to proliferate even in the industrial materials including organic solvents. These characteristic behaviors of the scuttle fly seem to be related to muscular and nervous system or neurotransmitters. Thus, we focused at the neurotransmitter, corazonin (Crz) that is known to be related to resistance to stress and investigated the developmental process of the neurons in the scuttle fly. Corazonin is a neuropeptide being expressed in the central nervous system (CNS) and is known to control mainly physiological functions and behaviors. Its many functions that have been proposed are still in controversy. In this studies, we found that there are three groups of corazoninergic neurons in the larval CNS of the scuttle fly and these neurons undergo distinguishable changes through metamorphic process compared to different fly species. Larva has 3 pairs of Crz neurons at the dorsolateral area of the brain, 1 pair at the dorsomedial brain and 8 pairs at the ventral nerve cord.

• Weed & Turfgrass Science
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• v.4 no.4
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• pp.338-347
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• 2015

Reinforcement cells are used to aid grass growth and taken together, this serves to extend greenery beyond the conventional spaces of lawns, tree pits, gardens, and parks, and is advantageous to urban cities since space for greening is often limited. Drought has variable effects on plant life and the resilience of turf to drought resistance also varies with species. Changes in photosynthetic ability were more pronounced for media rather than grass species. The media of sand without organic matter was found to be least suited for drought resistance. Normalized difference vegetation index (NDVI) and digital image analysis (DIA) data were generally in favour of Zoysia species as oppose to A. compressus. In A. compressus, selective traits such as, a more extensive root system and lower specific leaf area (SLA) were not an underlying factor that assisted this grass with enhanced drought resistance. Generally, WUE was found to be strongly related to plant characterises such as overall biomass, photosynthetic features as well as the lushness indexes, and specific leaf area. This study found a strong relationship between WUE and a suite of plant characteristics. These traits should serve as useful selection criteria for species with the ability to resist water stress.

• Communications of the Korean Mathematical Society
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• v.21 no.4
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• pp.701-717
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• 2006

The positive coexistence of a simple food chain model with ratio-dependent functional response and cross-diffusion is discussed. Especially, when a cross-diffusion is small enough, the existence of positive solutions of the system concerned can be expected. The extinction conditions for all three interacting species and for one or two of three species are studied. Moreover, when a cross-diffusion is sufficiently large, the extinction of prey species with cross-diffusion interaction to predator occurs. The method employed is the comparison argument for elliptic problem and fixed point theory in a positive cone on a Banach space.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.475-481
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• 2001

Sequences of ribosomal internal transcribed spaces (ITS) obtained from two Antrobia species and two related species were compared to investigate intrageneric and intergeneric phylogenetic relationships of Antrodia. The results showed that Antrodia species causing a brown rot in wood did not form a monophyletic clade and were separated into three distinct groups. Antrodia gossypina and A. vaillantii formed a clade having rhizomorphs as a homologous character. Antrodia serialis, A. sinuosa, and A. malicola formed a group together with Daedalea, Fomitopsis, and Postia species with brown rot habit. Antrodia xantha with a trimitic hyphal system and amyloid skeletal hyphae formed another distinct clade form other Antrodia species. The Antrodia species were separated from white rot genera such as Antrodiella, Diplomitoporus, Junghuhnia, and Steccherinum, indicating the phylogenetic importance of the rot type in the classification of the Polyporaceae.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.305-309
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• 2002

Raw soybean sprouts were tested for contamination with the following bacteria which have potential for pathogenesis or food spoilage : Salmonella spp., Escherichia coli O157:H7, Yersinia enterocolitica, Vibrio parahae-molyticus, Aeromonas hydrophila, Plesidomonas shigeloides, Pseudomonas aeruginosa, Staphylococcus aureus, Lis-teria monocytogenes, Bacillus cereus, Clostridium perfringens, Campylobacter jejuni, Erwinia spp., and Fusarium spp. Three of the above strains were isolated from the sprouts, and identified by morphological and biochemical methods including an API kit and ATB automated identification system. The isolate cultured in Cereus selective agar, a selective medium, was a Gram-positive, rod shaped, anaerobic spore former. The biochemical and culture tests revealed the following characteristics: catalase-positive, no growth on Simmon's citrate, NO₂ production and requirement of arginine for growth; the ATB automated identification system gave 99.8 % agreement for the identification of Bacillus cereus to the species level. The isolate cultured in Macconkey agar selective medium was Gram-negative, rod shaped and a gas former; the ATB-system gave 99.9% agreement for the identification of Aeromonas hydrophila to the species level. The isolate found in Pseudomonas isolation agar was Gram-negative, rod shaped, cytochrome oxidase-positive, a reducer of nitrates to nitrogen, and pyocyanin producer; the ATB-system gave 99.9 % agreement for the identification of Pseudomonas aeruginosa to the species level. These results indicate that the three bacteria species present in the soybean sprouts were Bacillus cereus, Aero-monas hydrophila, and Pseudomonas aeruginosa. Salmonella spp., Escherichia coli O157:H7, and Yersinia enter-ocolitica, which are associated with serious disease in humans, were not isolated from soybean sprouts examined in this study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.3
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• pp.196-205
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• 2023

This study investigated the species composition and bycatch status of fishes by fyke net between June and November 2020 in Asanho lake and Chungjuho lake. During the survey period, the catches in Asanho lake were identified as 2,931 individuals of 16 species from a total of six families and in Chungjuho lake were identified as 1,645 individuals of 14 species from a total of eight families. The dominant species in Asanho lake was Erythroculter erythropterus which accounted for 59.6% of the the total number of individuals and 40.5% of the total biomass caught. The dominant species in Chungjuho lake was Lepomis macrochirus which accounted for 48.2% of the the total number of individuals and Erythroculter erythropterus which accounted for 60.2% of the total biomass caught. The bycatch rates of non-commercial species in Asanho lake and Chungjuho lake were 77.0% and 82.6%, respectively. As a result of analyzing the frequency distribution of the total length of Carassius auratus and Siniperca scherzeri, which were the dominant species among commercial species, the bycatch rate of small individuals was 87.1%, and 42.7%, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.221-232
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• 2015

Broadband echoes measured in live chub mackerel Scomber japonicus, goldeye rockfish Sebastes thompsoni, and fat greenling Hexagrammos otakii with different morphologies and internal characteristics were analyzed in time and frequency domains to understand the species-specific echo feature characteristics for classifying fish species. The mean echo image for each time-frequency representation dataset obtained as a function of orientation angle was extracted to mitigate the effect of fish orientation on acoustic scattering. The joint time-frequency content of the broadband echo signals was obtained using the smoothed pseudo-Wigner-Ville distribution (SPWVD). The SPWVDs were analyzed for each echo signature of the three fish species. The results show that the time-frequency analysis provided species-specific echo structure patterns and metrics of the broadband acoustic signals to facilitate fish species classification.