• 한국환경과학회지
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• 제27권11호
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• pp.1007-1021
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• 2018

Community dynamics of benthic macroinvertebrates and biological evaluation of water quality were investigated at Gigyecheon of Pohang and Gyeongju, Korea. The survey was carried out at 8 sites from May to October, 2017. As a result, total of 104 species under 54 families, 15 orders, 8 classes in 4 phyla with 5,052 individuals were revealed. The number of species was the most abundantly identified in aquatic insects, 76 species under 34 families, 6 orders. Among them, the order Odonata was the most abundant taxon as 21 species(20.2%). The most abundant individuals were collected in the phylum Mollusca as 1,453 individuals(28.8%). Various species appeared dominantly at each site by season, and the most dominant species was Caridina denticulata denticulata belonging to the class Malacostraca with 0.08 of dominance index. According to the results of community structure analyses, the diversity and richness indices were the highest at site II, the evenness index was the highest at site I, and the dominance index was the highest at site IV. The number of species and individuals of gathering collectors were the highest among functional feeding groups. Those of sprawlers were the highest among habitat orientation groups. The ESB showed a tendency to change according to season and site, and it was the highest in May at most surveyed sites. The KSI was also somewhat fluctuated according to season and site. From these indices, average biological water quality was evaluated as class II.

• Journal of Species Research
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• 제8권4호
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• pp.380-388
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• 2019

We collected ciliate species from diverse habitats (brackish water, marine water, and terrestrial ecosystems) composed of estuarine, coast, and moss samples during 2017-2018 in Korea. The morphology and infraciliature of these species were examined and identified based on the observations of living cells and protargol impregnated specimens. Of the ciliates we identified, we described eight unrecorded species in Korea as followings: class Heterotrichea - Condylostoma vorax, Peritromus kahli; class Protocruziea - Protocruzia labiata; class Spirotrichea - Hemiamphisiella granulifera; class Litostomatea - Loxophyllum chinense; class Phyllopharyngea - Trochilioides recta; and class Oligohymenophorea -Cohnilembus verminus, Uronemella filificum. Among them, Protocruzia labiata is a poorly known species. In this paper, we provide the improved diagnoses and brief descriptions of the species with their microphotographs. The taxonomic classifications of the eight species are summarized as six classes, eight orders, five families, and eight genera. These voucher slides with protargol impregnated specimens have been deposited in the National Institutes.

• Journal of Species Research
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• 제8권2호
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• pp.247-248
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• 2019

• BMB Reports
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• 제49권12호
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• pp.681-686
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• 2016

Fructose 1,6-bisphosphate aldolase (FBA) is important for both glycolysis and gluconeogenesis in life. Class II (zinc dependent) FBA is an attractive target for the development of antibiotics against protozoa, bacteria, and fungi, and is also widely used to produce various high-value stereoisomers in the chemical and pharmaceutical industry. In this study, the crystal structures of class II Escherichia coli FBA (EcFBA) were determined from four different crystals, with resolutions between $1.8{\AA}$ and $2.0{\AA}$. Native EcFBA structures showed two separate sites of Zn1 (interior position) and Zn2 (active site surface position) for $Zn^{2+}$ ion. Citrate and TRIS bound EcFBA structures showed $Zn^{2+}$ position exclusively at Zn2. Crystallographic snapshots of EcFBA structures with and without ligand binding proposed the rationale of metal shift at the active site, which might be a hidden mechanism to keep the trace metal cofactor $Zn^{2+}$ within EcFBA without losing it.

• 대한수학회논문집
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• 제24권2호
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• pp.215-226
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• 2009

For a class of Holling type II food chain systems with biological and chemical controls, we give conditions of the local stability of prey-free periodic solutions and of the permanence of the system. Further, we show the system is uniformly bounded.

• Journal of Species Research
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• 제12권1호
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• pp.1-26
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• 2023

A faunal study on Amphipods belonging to the class Malacostraca was conducted 26-29 August 2021 at 12 sites in Chujado Island, Korea. This study found that 68 amphipod species in 39 genera, 19 families were living on Chujado Island. Among these 19 families, the family Caprellidae (20 species) showed the highest abundance. Ampithoidae (7 species) and Dexaminidae (6 species) were subdominant families. The species Stenothoe valida Dana, 1852 (found at 10 of 12 sites) was the most frequent and widespread species. Caprella scaura Templeton, 1836 was identified at 9 of 12 sites and had the highest frequency of appearance among 20 species of Caprellidae. Among the 68 species, Ampithoe waialua J.L. Barnard, 1970 and Melita nagatai Yamato, 1987 are newly recorded species in Korean fauna. These newly recorded species are fully illustrated and compared with related species. We provide an amphipod fauna in Chujado Island with a list, figures, and a table.

• Journal of Species Research
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• 제12권1호
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• pp.95-108
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• 2023

Ciliates are unicellular eukaryotes and one of the most abundant and speciose protistan groups. However, their diversity is underestimated, and many new species are waiting for our discovery. During several field surveys conducted from 2018 to 2021 to document indigenous Korean ciliates, 10 unrecorded ciliate species were collected and investigated from freshwater, marine, and semiterrestrial habitats. The morphology of these species was studied based on observation of living and protargol-stained specimens. These species belong to five classes as follows: 1) class Heterotrichea - Peritromus faurei; 2) class Spirotrichea - Heterotachysoma dragescoi, Pseudokeronopsis parasongi, and Certesia quadrinucleata; 3) class Nassophorea - Chilodontopsis depressa; 4) class Prostomatea - Plagiocampa rouxi and Urotricha furcata; and 5) class Oligohymenophorea - Metanophrys similis, Uronema gallicum, and Protocyclidium citrullus. Also, we provide a brief diagnosis, photomicrographs, and information of the locality for each species. Further, we compare each species with the most recent description and with similar congeners.

• Animal Bioscience
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• 제34권11호
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• pp.1749-1756
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• 2021

Objective: Microminipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs. Methods: The occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters. Results: The incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different. Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

• 한국균학회지
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• 제50권1호
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• pp.1-29
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• 2022

Hypocreales is one of the largest orders within the class Sordariomycetes in Ascomycota. Several species of this order are cosmopolitan and have a broad range of habitats. Here, we isolated several fungal strains from environmental samples, including freshwater sediment and plant litter. The strains were identified via molecular and phylogenetic analyses of rDNA and other DNA markers, such as TUB, RPB2, and EF1. The morphological characteristics of the fungi were investigated using microscopy, and culture characteristics were assessed from their growth on several media. We identified 17 species previously unrecorded in Korea: Dactylonectria hordeicola, Flavocillium bifurcatum, Fusarium luffae, Ilyonectria ilicicola, Ilyonectria qitaiheensis, Ilyonectria robusta, Lecanicillium aphanocladii, Nectria ulmicola, Neonectria lugdunensis, Ovicillium oosporum, Pseudonectria foliicola, Sarocladium spinificis, Scolecofusarium ciliatum, Trichoderma appalachiense, Trichoderma subviride, Trichoderma taiwanense, and Trichoderma tsugarense.

• Journal of Species Research
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• 제9권2호
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• pp.105-116
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• 2020

A total of 37 anaerobic bacteria strains within the classes Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Bacteroidia, Flavobacteriia, Bacilli, Clostridia, and Fusobacteriia were isolated from freshwater and sediment of the Geum River in Korea. The unreported species were related with Rhizobium and Oleomonas of the class Alphaproteobacteria; Acidovorax, Pseudogulbenkiania, and Aromatoleum of the class Betaproteobacteria; Tolumonas, Aeromonas, Cronobacter, Lonsdalea, and Phytobacter of the class Gammaproteobacteria; Bacteroides, Dysgonomonas, Macellibacteroides, and Parabacteroides of the class Bacteroidia; Flavobacterium of the class Flavobacteriia; Bacillus and Paenibacillus of the class Bacilli; Clostridium, Clostridioides, Paraclostridium, Romboutsia, Sporacetigenium, and Terrisporobacter of the class Clostridia; and Cetobacterium and Ilyobacter of the class Fusobacteriia. A total of 37 strains, with >98.7% 16S rRNA gene sequence similarity with validly published bacterial species, but not reported in Korea, were determined to be unrecorded anaerobic bacterial species in Korea.