• Korean Journal of Organic Agriculture
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• v.5 no.2
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• pp.93-104
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• 1997

In order to investigate the growth response of grasses to chitosan solution amended soil were studied from the standpoint of estimating the growth stimulating adequate concentrations of chitosan solution amended soil in each grass. Three species in this experiment used were orchardgrass, tall fescue and reed canarygrass. Six different concentrations of chitosan solution amended soil were 0%(control), 0.01%, 0.05%, 0.1%, 0.5% and 1.0%, respectively. The resulte obtained were as follows ; 1. Leaf area(LA), dry weight of leaf(LW), dry weight of shoot(SHW), biological yield(BY), C/f ratio and T/R ratio were significantly different between species. 2. Growth stimulating effect by chitosan solution amended soil were found in plant length(PL) and T/R ratios of grasses. 3. Adequate concentrations of chitosan solution amended soil were different between species. The highest values of yield components and dry weight of plant parts were obtained at 0.01% in orchardgrass, 0,05% in reed canarygrass and 1.0% in tall fescue, respectively. 4. The growth response of grasses to chitosan solution amended soil were different between species. Thus, an increase in leaf area(LA) and dry weight of leaf(LW) by chitosan solution amended soil was mainly contributed to increase in dry weight of shoot(SHW) and biological yield(BY) in orchardgrass. Chitosan solution amended soil also stimulated growth of shoot and increased in biological yield(BY) in tall fescue. In reed canarygrass contributed to increase in C/F ratios. 5. Adequate concentrations of chitosan solution amended soil for an economical benefit of cultivation and dry matter production of grasses were ranged from 0.01% to 0.05% levels.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.875-881
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• 2018

To select fruit trees suitable for shaded urban garden with Elaeagnus umbellata var. coreana, Malus domestica 'Alps Otome', Malus domestica 'Fujii', Prunus mume, Prunus persica for. persica, Rubus fructicosus, and Vaccinium corymbosum 'Reka', leaf growth in response to different light was investigated two years after 35% shade treatment. Leaf area of E. umbellata var. coreana, M. domestica 'Alps Otome', P. mume, P. persica for. persica, and V. corymbosum 'Reka' increased in shading. Fresh weight of leaves make inconsistent response to shading in every species but dry weight of E. umbellata var. coreana and P. persica for. persica showed the highest 150% and 148%, increment, respectively. Althought leaf water content of E. umbellata var. coreana decreased in shading, there is no difference in P. persica for. persica. Chlorophyll value of E. umbellata var. coreana and P. persica for. persica that showed higher than any other species is correlated with dark leaf green. Compared to specific leaf weight of E. umbellata var. coreana, P. persica for. persica, and V. corymbosum 'Reka' showed lower than any other species in shading, that of M. domestica 'Fujii', and R. fructicosus increased in reverse. These results indicate that E. umbellata var. coreana and P. persica for. persica that showed high value in several invesetigaton items are suitable for shady urban condition considering leaf growth in response to shading.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.582-590
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• 2023

Stress granules (SGs) are cytoplasmic aggregates of RNA-protein complexes that form in response to various cellular stresses and are known to restrict viral access to host translational machinery. However, the underlying molecular mechanisms of SGs during viral infections require further exploration. In this study, we evaluated the effect of SG formation on cellular responses to coxsackievirus B3 (CVB3) infection. Sodium arsenite (AS)-mediated SG formation suppressed cell death induced by tumor necrosis factor-alpha (TNF-a)/cycloheximide (CHX) treatment in HeLa cells, during which G3BP1, an essential SG component, contributed to the modulation of apoptosis pathways. SG formation in response to AS treatment blocked CVB3-mediated cell death, possibly via the reduction of mitochondrial reactive oxygen species. Furthermore, we examined whether AS treatment would affect small extracellular vesicle (sEV) formation and secretion during CVB3 infection and modulate human monocytic cell (THP-1) response. CVB3-enriched sEVs isolated from HeLa cells were able to infect and replicate THP-1 cells without causing cytotoxicity. Interestingly, sEVs from AS-treated HeLa cells inhibited CVB3 replication in THP-1 cells. These findings suggest that SG formation during CVB3 infection modulates cellular response by inhibiting the release of CVB3-enriched sEVs.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.5 no.3
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• pp.94-98
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• 2024

Field surveys for reports on suspected invasive termite species were received at the National Institute of Ecology's Invasive Species Reporting Center. We collected 10 termites and performed DNA sequence analysis for species identification. Specimens were confirmed as Coptotermes formosanus. This is the reconfirmation of C. formosanus in South Korea, highlighting the importance of early detection and rapid response and reaffirming the possibility of C. formosanus invading South Korea.

• Kyungpook Mathematical Journal
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• v.48 no.3
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• pp.515-527
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• 2008

We investigate a three species food chain system with a Holling type IV functional response and impulsive perturbations. We find conditions for local and global stabilities of prey(or predator) free periodic solutions by applying the Floquet theory and the comparison theorems.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.406-413
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• 2023

Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours.

• Journal of Forest and Environmental Science
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• v.29 no.2
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• pp.131-137
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• 2013

This study attempts to classify forest species using hyperspectral data for supporting resources management. The primary dataset used was AISA sensor. The sensor was mounted onboard the NOMAD GAF-27 aircraft at 2,000 m altitude creating a 2 m spatial resolution on the ground. Pre-processing was carried out with CALIGEO software, which automatically corrects for both geometric and radiometric distortions of the raw image data. The radiance data set was then converted to at-sensor reflectance derived from the FODIS sensor. Spectral Angle Mapper (SAM) technique was used for image classification. The spectra libraries for tree species were established after confirming the appropriate match between field spectra and pixel spectra. Results showed that the highest spectral signature in NIR range were Kembang Semangkok (Scaphium macropodum), followed by Meranti Sarang Punai (Shorea parvifolia) and Chengal (Neobalanocarpus hemii). Meanwhile, the lowest spectral response were Kasai (Pometia pinnata), Kelat (Eugenia spp.) and Merawan (Hopea beccariana), respectively. The overall accuracy obtained was 79%. Although the accuracy of SAM techniques is below the expectation level, SAM classifier was able to classify tropical tree species. In future it is believe that the most effective way of ground data collection is to use the ground object that has the strongest response to sensor for more significant tree signatures.

• Animal Systematics, Evolution and Diversity
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• v.40 no.1
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• pp.21-34
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• 2024

Two arenicolus halacarid species, Actacarus ornatus n. sp. and A. pacificus Bartsch, 1979, are recorded from sandy intertidal sediment along the coast of South Korea. Actacarus ornatus n. sp. closely resembles A. karoensis Abé, 1990, recorded from Japan, in having chaetotaxy of the idiosoma, legs, palps of gnathosoma, and perigenital setae in both males and females. However, it differs from A. karoensis by a slightly convex tectum, the presence of a row of foveae on the mid-ventral surfaces of the anterior epimeral plate and genitoanal plate, and the absence of areolae on both the anterior and posterior dorsal plates as well as microplatelets on the membranous cuticle alongside the anterior and posterior dorsal plates. Actacarus pacificus Bartsch, 1979, which is widely distributed in the Indo-Pacific region, is characterized by separated plates, a truncated tectum, the anterior epimeral plate with four pairs of setae, the posterior epimeral plate with one dorsal and two ventral setae, and three pairs of subgenital setae in males. A comparative analysis of the morphological characteristics of A. pacificus was conducted within regional populations, including the Korean population. Moreover, a key to Actacarus species from the northwestern Pacific, including a new species, is provided. The genus Actacarus is reported for the first time from Korea.

• Mycobiology
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• v.34 no.4
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• pp.191-195
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• 2006

This study was conducted to investigate the different effects of ectomycorrhizal fungal (ECMF) species on the growth of seedlings of Pinus densiflora, and the effects of ECMF diversity on plant productivity. A total of five species of ECMF were isolated from root tips of pine seedlings collected from Mt. Songni and used as inocula. Pots containing pine seedlings were inoculated with either a single ECMF species or a mixture of five ECMF species. All of the seedlings formed ECM on their roots except for the control plants. The pine seedlings' growth responses varied by the different ECMF species. Also, pine seedlings inoculated with a mixture of five ECMF species showed the highest growth response. The results of the study suggest that the colonization of diverse species of ECMF will increase plant productivity, and the selection of suitable ECMF species could be an important factor for plant growth.