• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.423-429
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• 2016

Cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. The main objectives of this study were to detect and identify Cryptosporidium species in captive snakes from exotic pet shops and snake farms in Thailand. In total, 165 fecal samples were examined from 8 snake species, boa constrictor (Boa constrictor constrictor), corn snake (Elaphe guttata), ball python (Python regius), milk snake (Lampropeltis triangulum), king snake (Lampropeltis getula), rock python (Python sebae), rainbow boa (Epicrates cenchria), and carpet python (Morelia spilota). Cryptosporidium oocysts were examined using the dimethyl sulfoxide (DMSO)-modified acid-fast staining and a molecular method based on nested-PCR, PCR-RFLP analysis, and sequencing amplification of the SSU rRNA gene. DMSO-modified acid-fast staining revealed the presence of Cryptosporidium oocysts in 12 out of 165 (7.3%) samples, whereas PCR produced positive results in 40 (24.2%) samples. Molecular characterization indicated the presence of Cryptosporidium parvum (mouse genotype) as the most common species in 24 samples (60%) from 5 species of snake followed by Cryptosporidium serpentis in 9 samples (22.5%) from 2 species of snake and Cryptosporidium muris in 3 samples (7.5%) from P. regius.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.892-901
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• 2012

The purpose of this research was to analyze fish fauna, distribution patterns, and fish community structures in the Juksan-Weir regions of upper weir(R-UW) and lower weir(R-LW), which was constructed in 2011 on Yeongsan River watershed. Our outcomes will provide valuable information in the impact analysis of weir constructions next decades, even if the current research is limited to distributions and fauna studies of fishes. The fishes observed were 8 family and 30 species in all the sites, and the number of the species in the regions of R-UW and R-LW was 23(938 individuals) and 27(1,680 individuals), respectively, indicating greater abundance in the lower region of Juksan-Weir. Most dominant species was Opsarichthys uncirostris amurensis with relative abundance of 42%, and this species had greater abundance in the R-LW(49%) than in the R-UW(30%). Coilia nasus, was the migratory fish sampled in this region and had no differences of abundance between the two regions. The extic species observed were Carassius cuvieri, Lepomis macrochirus, and Micropterus salmoides. The two formers of Carassius cuvieri(1.2%) and Lepomis macrochirus(3.7%) dominated in the R-UW, whereas Micropterus salmoides had greater dominance in the region of R-LW. According to tolerance guild analysis, the proportion of sensitive species ranged from 0.4 to 0.5%, and that of tolerant species ranged from 65% to 70%, implying a severe pollution of nutrients and organic matters in the water body. In the mean time, according to trophic guild analysis, the proportion of carnivores(57 - 77%) was evidently higher than that of insectivores(10 - 20%), indicating a dominance of the carnivores. Especially, high abundance of the bass, exotic species, may disturb the fish overall food chain, so the efficient ecosystem management may be required for the conservation of endemic species. When we examined fish data files of last 60 years, the species of Culter brevicauda, designated as endangered species, was observed firstly in our research area and the total number was 5 individuals(0.2% of the total). So, this region observed should be conserved as a protection zone and further monitoring studies should be done in the future.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.72-80
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• 2017

Fish fauna and community structures in freshwater were analyzed in the streams (12 stations) of the Bogil Island from May to September 2015. Total numbers of the sampled species and genus (9 families) were 21 and 17, respectively. Gobiidae was the most dominant taxa, which accounted for 47.6% (10 species) of the total species, and the relative abundance, based on the number of individuals, was 60.4% (1,157 individuals). Subdominant families were three taxa of Cyprinidae (3 species; 500 ind.), Mugilidae (2 species; 168 ind.) and Mugilidae (2 species; 128 ind.). The dominant species, based on the relative abundance, was Rhynchocypris oxycephalus (20.7%) and the subdominant species were Gymnogobius urotaenia (19.5%), Leucopsarion petersii (17.2%) and Chelon haematocheilus (8.5%). These species were composed of upstream-resident fish as well as migratory fishes, so the streams of the Bogil Island had unique characteristics in the fish compositions. Based on all the species sampled, 9 species (42.9%) were primary freshwater fishes, 11 species (52.4%) were peripheral fishes and 1 species (4.8%) was amphidromous fish. Korean endemic species and exotic species were not found in the streams of Bogil Island. According to the analysis of fish community structure, species richness index and species diversity index were highest (1.831, 1.957) in the Site 8 and lowest in the Site 4. In the meantime, the dominance index was highestin the Site 4 (1.00) and lowest in theSite 8 (0.17).

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.266-279
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• 2019

We investigated the characteristics of fish communities and habitat status of endangered species Rhodeus pseudosericeus in Heuk Stream, a tributary of the Han River, from April to October 2018. During this period, we collected 47 species of 14 families from 10 survey stations using kick nets, cast nets, and long bag set nets. The dominant and subdominant species were Zacco platypus (37.6%) and Z. koreanus (13.8%), respectively. The next most abundant species were Squalidus gracilis majimae (11.1%), Pungtungia herzi (7.7%), Rhodeus pseudosericeus (5.0%), Microphysogobio yaluensis (4.3%), and Hemibarbus longirostris (3.0%). Among the fish collected, 19 species (40.4%) were Korean endemic species. Endangered species were R. pseudosericeus and Acheilognathus signifer while exotic species were Micropterus salmoides and Oncorhynchus mykiss, and land-locked species were Plecoglossus altivelis and Rhinogobius brunneus. The community analysis showed that the dominance and evenness indexes were mostly low and that the diversity and richness indexes were high. Moreover, the river health (index of biological integrity) was mostly excllent (1 site is good, 9 sites are very good). R. pseudosericeus inhabited widely from St. 3 to St. 9 in Heuk Stream, and its population size was large. Age groups for R. pseudosericeus estimated by the frequency distribution of total length in spawning season (April) indicated the 32~45 mm group as 1-year old, the 46~59 mm group as 2-years old, 60~69 mm group as 3-years old, and the 70~89 mm group as 4-years or older. Total length range of male and female was similar, and the sex ratio of female (426) to male (394) was 1 : 0.95. A. signifer, which had been released in Heuk Stream, inhabited from St. 4 to St. 5, but its population size was small. Lastly, this paper discusses a conservation plan for fish in Heuk Stream.

• Journal of the Korean Wood Science and Technology
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• v.41 no.3
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• pp.201-210
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• 2013

The purpose of this study was to examine the species of 117 wooden elements which were used in the Daewungjeon Hall (National Treasure No. 805, constructed in A. D. 1659) of Bukjijangsa Temple, Daegu, Korea. Pillars were identified as 5 red pines (hard pines; most likely, Pinus densiflora S. et Z.), 2 Cerris section of subgenus Lepidobalanus (deciduous oaks) and 3 Tsuga spp. Hwalju columns were 3 Abies spp. and 1 red pine. Head-penetrating ties were 8 red pines and 1 Cerris sp.; Pyeongbang, 3 red pines and 6 Cerris spp. Purlins were identified as 17 red pines, 16 Cerris spp. and 1 Tsuga sp. Angle rafters were 3 red pines and 1 Cerris sp., and end angle rafters, 2 red pines, 1 Zelkova serrata and 1 exotic hard pine. All of brackets (31 woods), jangyeo (4) and deot-chunyeo (2) were identified as red pines. As a whole, red pines (70.1%) and Cerris (22.2%) were major species used in the Daewungjeon Hall of Bukjijangsa Temple. Tsuga, Abies and exotic hard pines seem imported woods used for recent repairs.

• Korean Journal of Environment and Ecology
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• v.17 no.2
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• pp.123-132
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• 2003

This ecological study investigated the vegetation changes of abandoned salt field, 21 plots(1${\times}$lm, 1${\times}$2m) set up by the methods of Braun-Blanquet and Elenberg in a coastal island, Gasado, Jindogun, from July to September,2002. The vascular plants of abandoned salt field in the surveyed site identified 17 families and 48 species. Of these species, halophytes and mesophytes were 20(42%) and 28(58%) species. In addition, the disturbance to this habitat led to the change of halophytes in abandoned sald field, exotic plants was distributed 23 species, which included Dactylis glomerata, Conyza canadensis, Oenothera odorata, Cosmos bipinnatus, etc., in the group of, mesophytes were 20(71%) species, vegetation communities were classified into 3 community types, i.e. the halophyte grassland community(Limonium tetragonum community, Suaeda japonica community, Spergularia marina community), the wetland grassland community(Phragmites communis community, Carex scabrifolia community, Phaceturus latifolius var. angustifolius community), and the mesophyte grassland community(Erigeron bonariensis community, Daucus littoralis var. koreana community). Each communities was described the structual, distribution and changes of the vegetation in the abandoned salt field, the vegetation table and actual vegetation map were prepared.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.143-148
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• 2007

The introduced exotic species has often caused severe problems to the native ecosystem. One of such species is the freshwater fish gengorobuna (Carassius cuvieri) introduced from Japan. The first step to assess harmful effects of this species on the Korean freshwater ecosystem is to discriminate it from the most similar native crucian carp (Carassius auratus). Because traditional morphological identification often gives unreliable results due to their highly similar phenotype, a new more efficient method is needed. For this purpose, molecular markers produced by the efficient one-step PCR method using three primers (DDF, DDR and DDR1) were developed and tested in the present study. This molecular marker will play an important role in monitoring fish community of Korean freshwater ecosystem.

• Journal of Environmental Science International
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• v.21 no.11
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• pp.1307-1320
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• 2012

The purpose of this paper is to provide information on planting construction for healthy plant growth. To achieve this purpose, this study analyzed the planting type, planting density, withering rate, soil characteristics, and cambium electrical resistance (CER) of withered trees in an apartment complex with a high withering rate. The major plant groups examined consisted of native broad-leaved tree species (39.3%), native narrow-leaved tree species (24.2%), and native broad-leaved - exotic narrow-leaved tree species (16.4%). The planting density of the green area, where trees were planted from 0.0 to 0.3 trees per unit area, was measured as 98.4%. Withered trees were found in 19 of the 20 planted species, and the withering rate was 41.8% (610 withered/1,461 planted). Withering rates for tree species were measured as follows: Sophora japonica and Salix babylonica (100.0%), Magmolia denudata (84.3%), Lindera obtusiloba (74.7%), cornus kousa (69.3%), acer triflorum (69.2%), diospyros kaki (66.7%), Prunus yedoensis (62.8%), Acer palmatum (52.6%), Prunus armeniaca (51.1%), Chaenomeles sinensis (43.7%), Ginkgo biloba (40.9%), Zelkova serrata (31.0%), Cornus officinalis (28.6%), Taxus cuspidata (25.6%), Pinus densiflora (21.4%), Pinus parviflora (15.2%), Pinus strobus (14.6%), and Abies holophylla (10.3%). Soil chemical analyses for 18 samples revealed that as the withering rate increased, the following occurred: (a) the ratio of silt and clay in soil increased; (b) the soil pH, organic matter rate, nitrogen, available phosphorus, and cation exchange capacity (CEC) in samples were graded as "inadequate," based on the plant grading evaluation; and (c) the NaCl and cation exchange capacity were evaluated as "somewhat satisfactory." The measurement of CER for withering rate shows electrical resistance for higher withering rate are higher, which could predict that a tree will not grow well.

• Journal of architectural history
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• v.15 no.2
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• pp.23-38
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• 2006

During the repair and restoration of the Daewoongjeon Hall of Youngguksa Temple, species identification and tree-ring dating for both present wood elements and charred ones excavated under the Hall, were conducted. The species of 74 wood elements of Daewoongjeon Hall, were identified as Pinus densiflora Sieb. et Zucc. and only 1 was identified as exotic Pinus species. The latter wood, which was used in the laths, seems to have been replaced during past repairs. Many documentary records and various artifacts pertaining to Youngguksa Temple are being excavated, but none described precisely the construction date of the present Daewoongjeon Hall. Also, from beneath the Daewoongjeon Hall, cornerstone and foundation of previous building and several charred wood elements were excavated. In comparing the direction of the stone columns of foundation of the previous structure and the existing Daewoongjeon Hall, the previous structure was rotated in an angle of approximately $15^{\circ}$. Therefore, in order to find the association of the previous structure with the present Daewoongjeon Hall, tree-ring dating was conducted. The dating of 41 original timbers and 14 roof-filling timbers of the present construction elements revealed that the last annual ring was of A. D. 1703 with complete latewood, indicating that those woods was cut some time between the autumn of 1703 and spring of 1704, and the building was erected in 1704 when we assume no period of wood storage. The year of the last annual ring of the charred elements, which were excavated from beneath the Daewoongjeon Hall, was analyzed as 1674. The cutting year of the woods used for the present building began in 1698, therefore, it can be presumed that the Daewoongjeon Hall before the fire was a structure that was elected shortly after 1674 and that a catastrophic fire occurred some time between 1674 and 1698.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.159-175
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• 2015

Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.