• 한국수산과학회지
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• 제37권2호
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• pp.122-128
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• 2004

On the basis of monthly samples, we investigated the seasonal variation and feeding habits of amphipods inhabiting Zostera marina beds in Gwangyang Bay. Dominant species $(>1\%$ of the total number of amphipods) consist of 5 gammarids (Gammaropsis japonicus, Jassa slatteryi, Pontogenia rostrata, Atylus collingi and Ceinina japonica) and 1 caprellid (Caprella tsugarensis). Mean densities of amphipods varied from the highest of $63,148\;ind.\;m^{-2}$ in-May to the lowest of $1,247\;ind.\;m^{-2}$ in September. G. japonicus and J. slatteryi dominated in summer whereas C. japonica in autumn and winter. C. japonica was found to be a carnivorous feeder consuming mainly harpacticoid copepods and unidentified crustaceans, whereas G. japonicus, J. slatteryi, and C. tsugarensis consumed both phytoplankton and detritus. Seasonal densities of amphipods were significantly related with the shoot standing crop of the eelgrass and its epiphyte. Also densities of amphipods displayed significant difference in related with the shoot density of the eelgrass among sampling stations. These results suggest that the biological interactions between the eelgrass and amphipods as well as between the carnivorous and the herbivorous amphipods may be important in the seasonal variation of amphipods inhabiting Z. marine beds.

• 한국수산과학회지
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• 제50권5호
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• pp.624-629
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• 2017

A rainbow trout Onchorhynchus mykiss farm located in Gangwon province, South Korea, experienced approximately 10% mortality in June 2017. Most diseased fish had a markedly distended, gas-filled stomach, and exhibited abnormal behavior at the water surface. In this study, we attempted to identify the cause of stomach distension syndrome in those rainbow trout. The stomach of most of the affected fish were full of unidentified gases and some exudate, and yeast was isolated from the stomach mucosa. Pure cultures of yeast were identified using a multilocus sequence typing scheme based on 18S rRNA, internal transcribed spacers, large subunit rRNA, and the gene encoding the largest subunit of RNA polymerase II (RPB1). The RPB1 gene sequences were compared with those of related species available in a database. The yeast was identified as Scheffersomyces coipomoensis (Candida coipomoensis) based on sequence analyses. This is the first study to reveal that Sch. coipomoensis is a potential causative agent of stomach distension syndrome in farmed rainbow trout. Our results will be helpful for future related studies, and indicate that farmers and stakeholders should observe this emerging disease closely.

• Environmental Engineering Research
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• 제12권3호
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• pp.101-108
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• 2007

Fixation of lead contaminants in the solidification/stabilization using Portland cement has been investigated by X-ray diffraction, scanning electron microscopy and compressive strength. The presence of lead was observed to produce lead carbonate sulfate hydroxide ($Pb_4SO_4(CO_3)_2(OH)_2$), lead carbonate hydroxide hydrate ($3PbCO_3{\cdot}2Pb(OH)_2{\cdot}H_2O$) and two other unidentified lead salts in cavity areas and was observed to significantly retard the hydration of cement. By 28 days, howevere, the XRD peaks of most of the lead precipitates have essentially disappeared with only residual traces of lead carbonate sulfate hydroxide and lead carbonate hydroxide hydrate evident. After 28 days of curing, hydration appears well advanced with a strong portlandite peak present though C-S-H gel peaks are not particularly evident. Lead species produced with the dissolution of lead precipitates are fixed into the cement matrix to be calcium lead silicate hydrate (C-Pb-S-H) during cement-based solidification.

• 미생물학회지
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• 제18권2호
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• pp.73-90
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• 1980

Ninerty one of Trichoderma spp. were isolated from ginseng growing bed, dead trees and muchroom in Korea from March 1978 to June 1979. Six species were identified as T. hamatum(13 strains), T, roningii(17 strains), T. aureoviride(4 strains), but other six strains(strain No. 111, 125, 127, 130, and 503) unidentified by Rifai's key. The reason which is not identified is as following. According to Rifai's key, phialid, phialospore and colony's colour of four strains (strain No. 125, 126, 127 and 130) are like T. longibrachiatum, but they are different from Rifai's method, because sterile-hypha often appears. the fature of standard strain ATCC no. 13631 T. longibrachiatum is like ster9ile-hypha that is used strains in this experiment. The morphology of strain No.503 is the same as T. hamatum except phialospore. Gnerally, T. hamatum's phialospore is subcylindrical, but strain No. 503 is regular ovoid. Therefore, strain No.503 cannot be identified by Rifai's key. The property, strain No.111's phialid is very irregular $(5{\sim}20{\times}2{\sim}2.5{\mu})$) and its phialospore $(4.0{\sim}6.0{\times}3.0{\sim}4.0{\mu})$) is subcylindrical, is uncomfortable to Rifai's method. The standard strains used in this experiment are 7 kinds of Trichoderma spp. received from ATCC.

• ALGAE
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• 제23권2호
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• pp.115-118
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• 2008

Cells of the dinoflagellate Peridinium were frequently observed in water samples of Togyo reservoir, and some species were responsible for dense blooms. Recently, we could identify them as P. bipes f. occultatum Lindem. and P. aciculiferum Lemm., considering morphology (Ki et al. 2005a; Ki and Han 2005b): However, some unidentified Peridinium cells with different shapes and body sizes were found among the samples collected during early spring. Here we describe their morphological characteristics such as thecal plate and body size to characterize its taxonomic identity by morphological characters. The formula of epithecal plates was recorded as 4 apical, 2 intercalary and 7 precingular plates (i.e. 4’', 2a, 7’'’') and the epicone in an apical view was symmetric. An apical pore was easy to make out under a light microscope. No cingular displacement was observed. The average body size was 33 $\mu$m in length with a range of 26-36 $\mu$m, and average 26 $\mu$m in width with a range of 21-31 $\mu$m, respectively; the cell was, therefore, shown slightly elongated. This way we identified Peridinium umbonatum Stein, 1883 for the first time from Korean freshwaters.

• The Plant Pathology Journal
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• 제23권4호
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• pp.287-294
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• 2007

Endophytic fungi were isolated from surface sterilized root tissues of Aralia elata and Aralia continentalis, collected from farmer's field in Chungnam province, Republic of Korea, in 2005. Based on ITS sequence analysis, 24 fungal genera were characterized from 359 isolates, belonging to 22 Ascomycota, 1 Glomeromycota and 1 Oomycota. Strumella, Rhizopycnis and Entrophospora in A. elata and Rhizopycnis and Leptosphaeria in A. continentalis were the most abundant taxa. Out of 24 genera, Entrophospora, Leptodontidium, Neoplaconema, Paraconiothyrium, Rhizopycnis, Strumella and Tumularia were new to Korea. A total of 110 isolates were tested for antifungal activities against six plant pathogenic fungi. Out of these, 39 isolates showed antifungal activity against at least one plant pathogenic fungi. Four isolates of Pyrenochaeta, 1 isolate of Entrophospora and 1 unidentified fungus strongly inhibited the growth of six plant pathogenic fungi.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.668-674
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• 2017

Experimental verification of boron species in fuel CRUD (Chalk River Unidentified Deposit) would provide essential and important information about the root cause of CRUD-induced power shifts (CIPS). To date, only bonaccordite and elemental boron were reported to exist in fuel CRUD in CIPS-troubled pressurized water reactor (PWR) cores and lithium tetraborate to exist in simulated PWR fuel CRUD from some autoclave tests. We have reevaluated previous analysis of similar threadlike crystals along with examining some similar threadlike crystals from CRUD samples collected from a PWR cycle that had no indications of CIPS. These threadlike crystals have a typical [Ni]/[Fe] atomic ratio of ~2 and similar crystal morphology as the one (bonaccordite) reported previously. In addition to electron diffraction study, we have applied electron energy loss spectroscopy to determine boron content in such a crystal and found a good agreement with that of bonaccordite. Surprisingly, such crystals seem to appear also on corroded surfaces of Alloy 600 that was exposed to simulated PWR primary water with a dissolved hydrogen level of $5mL\;H_2/kg\;H_2O$, but absent when exposed under $75mL\;H_2/kg\;H_2O$ condition. It remains to be verified as to what extent and in which chemical environment this phase would be formed in PWR primary systems.

• 한국균학회지
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• 제26권1호통권84호
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• pp.97-102
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• 1998

제주도 일원 14개소의 감귤원에서 감귤 뿌리를 포함한 토양 시료를 95년 10월에 수집하여 VA균의 포자를 분리하여 관찰 동정하였다. 분리된 공생균근균은 3속 5종으로서 Acaulospora bireticulata, Glomus deserticola, G. geosporum, G. vesiculiferum, Sclerocystis pachycaulis였으며, Acaulospora sp.로 사료되는 두 가지는 아직 종동정이 되지 않았다. 이중에서 G. deserticola와 미동정된 Acaulospora sp.는 모든 시료토양에서 빈도가 매우 높게 관찰되어 우점종으로 사료되었으나, 다른 종에 속하는 포자들은 이들 종에 비하여 관찰 빈도가 매우 낮았다.

• Journal of Ecology and Environment
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• 제29권4호
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• pp.381-387
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• 2006

We analyzed the total yields and composition of essential oils in leaf extracts of Nepeta cataria by Gas Chromatography Mass Spectrometry (GC-MS). Thirty-six compounds representing 97.0% of total oil were detected. The major constituents of essential oils in Nepeta cataria were nepetalactone (90.9%), unidentified compound (Retention time 17.35; 1.82%), 1,8-cineol (1.49%), ${\beta}-caryophyllene$ (1.12%), and ${\beta}-pinene$ (1.078%). The volatile compounds in leaf extracts of N. cataria concentrated to nepetalactone ($88.83{\sim}93.33%$) remarkably. In the essential oil of N. cataria cis,trans-nepetalactone ($30.2{\sim}37.8%$) and cis,cis-nepetalactone ($31.5{\sim}37.0%$) were found as the main constituents. The effects of essential oil of N. cataria on the growth of six microorganisms (Bacillus cereus, B. subtilis, B. amyloliquefaciens, Escherichia coli, Staphylococcus aureus subsp. aureus, and Pseudomonas aeruginosa) were investigated. The essential oil of N. cataria had strong inhibitory effect on the growth of three fungal species (Bacillus cereus, B. subtilis, and B. amyloliquefaciens). The essential oil from N. cataria was found to have a low antimicrobial activity against Staphylococcus aureus subsp. aureus, while no activity were found against Escherichia coli and Pseudomonas aeruginosa. Results indicate the significant antimicrobial effect, which may be depended on the yield of nepetalactone.

• The Korean Journal of Physiology and Pharmacology
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• 제25권3호
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• pp.251-258
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• 2021

Flos magnoliae (FM), the dry flower buds of Magnolia officinalis or its related species, is a traditional herbal medicine commonly used in Asia for symptomatic relief of and treating allergic rhinitis, headache, and sinusitis. Although several studies have reported the effects of FM on store-operated calcium entry (SOCE) via the ORAI1 channel, which is essential during intracellular calcium signaling cascade generation for T cell activation and mast cell degranulation, the effects of its isolated constituents on SOCE remain unidentified. Therefore, we investigated which of the five major constituents of 30% ethanoic FM (vanillic acid, tiliroside, eudesmin, magnolin, and fargesin) inhibit SOCE and their physiological effects on immune cells. The conventional whole-cell patch clamp results showed that fargesin, magnolin, and eudesmin significantly inhibited SOCE and thus human primary CD4+ T lymphocyte proliferation, as well as allergen-induced histamine release in mast cells. Among them, fargesin demonstrated the most potent inhibitory effects not only on ORAI1 (IC50 = 12.46 ± 1.300 μM) but also on T-cell proliferation (by 87.74% ± 1.835%) and mast cell degranulation (by 20.11% ± 5.366%) at 100 μM. Our findings suggest that fargesin can be a promising candidate for the development of therapeutic drugs to treat allergic diseases.