• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.298-309
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• 2001

The purpose of this study was to evaluate the filtering-feeding effect of a freshwater mussel (Corbicula leana) on the phytoplankton communities in two lakes with different trophic conditions between June and September, 2000. Manipulation experiments were conducted with two treatments (the control and mussel addition), and each established in duplicate 10 l chambers. Both ambient nutrient (TN, TP) and chlorophyll-a concentrations were significantly (p<0.01) higher in Lake Ilgam than Lake Soyang. Cyanophytes (Microcystis, Oscillatoria, Lyngbya and Dactylococcopis) consistently dominated algal community in Lake llgam, while flagellated algae (Dinobryon divergence, Mallomonas, Rhodomonas) and cyanophytes (Microcystis)dominated in Lake Soyang. The net exponential death rate ($R\;=\;day^{-1}$) of total phytoplankton in the mussel treatment ranged $1.70{\sim}7.39$ and $0.38{\sim}1.64$ in Lakes Soyang and Ilgam, respectively. Mean filtering rate standardized by mussel AFDW ($ml\;mgAFDW^{1}\;h^{-1}$) was much higher in Lake Soyang ($1.70{\sim}3.06$) than in Lake Ilgam($0.24{\sim}0.88$0.24~o.88). Estimating FR per mussel, 1 mussel filtered $1.6{\sim}7.8\;l$ per day and $1.7{\sim}3.0\;l$ per day in Lakes Soyang and Ilgam, respectively. Based on tile C-flux tobiomass ratio, Corbicula leana consumed $0.8{\sim}4.4$ fold of phytoplankton standing stock in Lake Soyang, and $0.4{\sim}1.6$ fold in Lake Ilgam per day. Mussel feeding resulted in increase of SRP concentration by $30{\sim}50%$, compared with the control. The results of this study suggest that filter-feeding activity of Corbicula leana varies depending on the phytoplankton density and community composition. The high seston consumption rate of Corsicuja Jeaua even in a eutrophic lake suggests that biomanipulation approach using filter-feeding mussels can be used far wate rquality management in small eutrophic reservoirs.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.303-309
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• 2005

This study was conducted to examine the effects of OA on metaphase of meiosis II and the mitochondrial activity of cytoplasm in bovine cumulus oocytes complexes(COCs) during in vitro maturation. Hanwoo COCs were collected from the slaughterhouse cow ovaries and matured in TCM199 supplemented with $0.1\%$ PVA, 0.2 uM, 2 uM, 20 uM OA for the maturation rate of OA concentration. For the maturation effects between OA and cycloheximide(CX), COCs were matured in TCM199 with 25 ug/mL CX, 25 ug/mL CX (6 hrs culture) plus 2 uM OA or 2 uM OA only at a atmosphere $5\%\;CO_2,\;95\%$ air $39^{\circ}C$ for 6, 12, 24 hrs. To evaluate the nuclear types of matured COCs, cumulus cells were removedby $0.5\%$ hyaluronidase sol. and oocytes were fixed in 1:3 acetic acid ethyl alcohol for 30 sec. and then stained with $0.1\%$ basic Fuchsin sol. For the detection of fluoriscent intensity (FI) of matures oocytes, cumulus cells were removed same as performed above and were stained with 20 nM mite tracker for 20 min. at $39^{\circ}C$. Mitochondrial activity of FI in matured oocytes was imaged by laser conforcal microscopy (Fluoview, Olympus, Japan) and were measured scanned face on 5 um from median to endpoint of oocytes. Statical analysis of nuclear types observed the three replicates was carried out with ANOVA and Fisher's protected least significant difference test using the STATVIEW program. FI of matures oocytes was compared the multiples of the least intensity among the measured oocytes. Maturing in TCM199 supplemented with $0.1\%$ PVA, 0.2 uM, 2 uM, 20 uM OA, metaphase B were showed 72.0, 50.0, 70.0, $68.8\%$, respectively and there were different significant(p<0.05). In the case of treatment with OA and CX, metaphase were $73.8\%,\;8.2\%,\;45.5\%,\;73.7\%$ in $0.1\%$ PVA-TCM199, 25 ug/mL CX, 25 ug/mL CX plus OA or 2uM OA only, respeclively. FI was revealed the increasing tendency during the process of maturation. Whereas FI in CX was decreased about 3 times compared to the other treatments of 6 hrs maturation. We conclude that OA regulates bovine COCs maturation and induces the mitochondrial activity during the process of maturation.

• Animal cells and systems
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• v.7 no.4
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• pp.309-315
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• 2003

Renal dipeptidase (RDPase, membrane dipeptidase, dehydropeptidase 1, EC 3.4.13.19) has been widely studied since it was first purified from porcine kidney brush border membrane. It was reported that RDPase activity in urine samples of acute and chronic renal failure patients decreases. Nitric oxide (NO) is a highly reactive free radical involved in a number of physiological and pathological processes. NO is able to act in a dual mode, leading either to induction of apoptosis or to blunted execution of programmed cell death. NO inhibited the RDPase release from porcine renal proximal tubules, which could be blocked by L-NAME. Chitosan, the linear polymer of D-glucosamine in $\beta$(1\longrightarrow4) linkage, not only reversed the decreased RDPase release by NO but also increased NO production in the proximal tubule cells. The stimulatory effect of NO on RDPase release from proximal tubules in the presence of chitosan must be different from the previously proposed mechanism of RDPase release via NO signaling pathway. Chitosan stimulated the RDPase release in the proximal tubules and increased RDPase activity to 220% and 250% at 0.1% and 1%, respectively. RDPase release was decreased to about 40% in the injured proximal tubules and was recovered in proportion to the increase of chitosan. Chitosan may be useful in recovery of renal function from $HgCl_2$injury.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.4
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• pp.309-314
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• 2005

We performed a basic experiment for the rapid, on-line, real-time measurement of hepatitis B surface antigen using a surface plasmon resonance biosensor. We immobilized anti­HBsAg (hepatitis B surface antigen) polyclonal antibody, as a ligand, to the dextran layer on a CM5 chip surface that had previously been activated by N-hydroxysuccinimide. A sample solution containing HBsAg was fed through a microfluidic channel, and the reflecting angle change due to the mass increase from the binding was detected. The binding characteristics between HBsAg and its polyclonal antibody followed the typical monolayer adsorption isotherm. When the entire immobilized antibody had interacted, no additional, non-specific binding occurred, suggesting the immunoreaction was very specific. The bound antigen per unit mass of the antibody was independent of the immobilized ligand density. No significant steric hindrance was observed at an immobilization density of approximately $17.6 ng/mm^2$. The relationship between the HBsAg concentration in the sample solution and the antigen bound to the ligand was linear up to ca. $40{\mu}g$/mL. This linearity was much higher than that of the ELISA method. It appeared the anti­gen-antibody binding increased as the immobilized ligand density increased. In summary, this study showed the potential of this SPR biosensor-based method as a rapid, simple and multi­sample on-line assay. Once properly validated, it may serve as a more efficient method for HBsAg quantification for replacing the ELISA.

• The Journal of the Petrological Society of Korea
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• v.8 no.1
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• pp.46-55
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• 1999

Fluid inclusions in granite and hydrothermal quartz indicate that three fluids have affected the Sannae granite. The earliest fluid is represented by three-phase aqueous fluid inclusions with high salinity (38 to 46 wt.% NaCl equiv.). It was exsolves from a crystallizing melt and trapped at a relatively high-pressure condition. The secong fluid is represented by two-phase aqueous fluid inclusion with low entectic temperatures (< $-40^{\circ}C$). low- to moderate salinity (3 to 24.0 wt.% NaCl equiv.) and high homogenization temperatures$ ($309^{\circ}C$$473^{\circ}C$)($. This fluid was trapped at higher pressures than 300-500 bars and precipitated molybdenite and wolframite in quartz veins. It was probably generted by fluid-host rock interactions since they show a wide range of salinity within a narrow range of homogenization temperatures. The final fluid is represented by an aquenous fluid boiling that separated into high-salinity (34-38 wt.% NaCl equiv.) and low-salinity fluid (0 to 8.7 wt.%) at $303-376^{\circ}C$ and 50-150 bars. These boiling fluids precipitated euhedral quartz in miarolitic cavities. The compositions of the final fluid was rather complex in the $H_2$O-NaCl-KCI-$FeCl_2$ system. The Sannae granite was a locus for repeated fluid events including magmatic fluids during the final stage of crystallization, the convection of hydrothermal fluids causing a fluid ascending, fluid boiling, and the local W-Mo mineralization and formation of miarolitic cavities due to thermal, tectonic and compositional properties of the felsic granite.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.303-309
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• 1995

An experiment was camed out in 1994 to determine the effects of curing periods and preservatives on the characteristics and forage quality of baled alfalfa(Medicago sativa L.) hay after 60 days of storage. The main plots consisted of the curing periods such as 5 and 7 days, and the subplots consisted of preservatives such as commercial propionic acid preservative, lactic inoculant and control. Temperature during storage remained lower in 7 days cured hay bale than in 5 days and didn't rise over $30^{\circle}C$ in 7 days cured hay bale. After storage, bale with 7 days curing remained in better condition by visual assessment and DM loss of the bale was 21.4% with 5 days curing and 11.8% with 7 days curing. ADF and NDF contents of 5 days cured baled hay were 43.0 and 56.1%. respectively, which were lower than those of 7 days cured baled hay by 1.3 and 1.4%, respectively(P< 0.05). ADF and NDF contents of preservative treated baled hay were higher than those of the control(P<0.05). According to RFV, forage quality of the control and inoculant treated baled hay of 5 days curing, and the control of 7 days curing was classified as 3rd grade, but other baled hay was classified as 4th grade. The total nitrogen content of 5 days cured baled hay was 1.84% and 7 days was 1.38%(P<0.05). Significant differences(P<0.05) in total N content of baled alfalfa hay were found among the preservatives. ADIN/total N of 5 and 7 days cured baled alfalfa hays was 28 and 26%. respectively.

• Journal of Astronomy and Space Sciences
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• v.31 no.4
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• pp.303-309
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• 2014

The Earth's outer radiation belt often suffers from drastic changes in the electron fluxes. Since the electrons can be a potential threat to satellites, efforts have long been made to model and predict electron flux variations. In this paper, we describe a prediction model for the outer belt electrons that we have recently developed at Chungbuk National University. The model is based on a one-dimensional radial diffusion equation with observationally determined specifications of a few major ingredients in the following way. First, the boundary condition of the outer edge of the outer belt is specified by empirical functions that we determine using the THEMIS satellite observations of energetic electrons near the boundary. Second, the plasmapause locations are specified by empirical functions that we determine using the electron density data of THEMIS. Third, the model incorporates the local acceleration effect by chorus waves into the one-dimensional radial diffusion equation. We determine this chorus acceleration effect by first obtaining an empirical formula of chorus intensity as a function of drift shell parameter $L^*$, incorporating it as a source term in the one-dimensional diffusion equation, and lastly calibrating the term to best agree with observations of a certain interval. We present a comparison of the model run results with and without the chorus acceleration effect, demonstrating that the chorus effect has been incorporated into the model to a reasonable degree.

• ALGAE
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• v.32 no.4
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• pp.309-324
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• 2017

Recently, the heterotrophic nanoflagellate Katablepharis japonica has been reported to feed on diverse red-tide species and contribute to the decline of red tides. However, if there are effective predators feeding on K. japonica, its effect on red tide dynamics may be reduced. To investigate potential effective protist predators of K. japonica, feeding by the engulfment-feeding heterotrophic dinoflagellates (HTDs) Oxyrrhis marina, Gyrodinium dominans, Gyrodinium moestrupii, Polykrikos kofoidii, and Noctiluca scintillans, the peduncle-feeding HTDs Luciella masanensis and Pfiesteria piscicida, the pallium-feeding HTD Oblea rotunda, and the naked ciliates Strombidium sp. (approximately $20{\mu}m$ in cell length), Pelagostrobilidium sp., and Miamiensis sp. on K. japonica was explored. We found that none of these heterotrophic protists fed on actively swimming cells of K. japonica. However, O. marina, G. dominans, L. masanensis, and P. piscicida were able to feed on heat-killed K. japonica. Thus, actively swimming behavior of K. japonica may affect feeding by these heterotrophic protists on K. japonica. To the contrary, K. japonica was able to feed on O. marina, P. kofoidii, O. rotunda, Miamiensis sp., Pelagostrobilidium sp., and Strombidium sp. However, the specific growth rates of O. marina did not differ significantly among nine different K. japonica concentrations. Thus, K. japonica may not affect growth of O. marina. Our findings suggest that the effect of predation by heterotrophic protists on K. japonica might be negligible, and thus, the effect of grazing by K. japonica on populations of red-tide species may not be reduced by mortality due to predation by protists.

• Clinical and Experimental Pediatrics
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• v.57 no.1
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• pp.29-34
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• 2014

Purpose: In this study, we aimed to investigate the prevalence of year-round respiratory viral infection in children with lower respiratory tract infection (LRTI) and the relationship between respiratory viral infection and allergen sensitization in exacerbating asthma. Methods: We investigated the sources for acute LRTIs in children admitted to our hospital from May 2010 to April 2011. The 6 most common respiratory viruses were isolated from nasopharyngeal aspirate using multiplex reverse transcription-polymerase chain reaction in 309 children; respiratory syncytial virus (RSV), adenovirus (AV), parainfluenza virus (PIV), influenza virus (IFV), human metapneumovirus (hMPV), rhinovirus (RV). Atopic sensitization was defined if more than 1 serum specific Immunoglobulin E level measured using UniCAP (Pharmacia) was over 0.35 IU/mL. Results: RSV was the most common pathogen of bronchiolitis in hospitalized children through the year. RV or IFV infection was more prevalent in asthma exacerbations compared to other LRTIs. AV and hMPV were more likely to cause pneumonia. RV and IFV were associated with asthma exacerbations in children with atopic sensitization, but not in nonatopic children. Conclusion: RV and IFV are associated with hospitalization for asthma exacerbation in children with atopic sensitization.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.309-315
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• 2012

Objectives: Animal husbandry workers could be exposed to various work hazards including toxic gases, chemicals such as pesticides or organic dust. Immunological evaluation focusing on respiratory allergic hypersensitivity occurrence was under-taken for swine farm workers as a part of the study on immunologic status of dairy barn, swine confinement, and poultry farm workers. Materials and Methods: Peripheral bloods were collected from 25 workers at the year of 2001 and 12 workers at the year of 2012 from swine farms located at Gyeonggi province, Korea. Seven adults not involved with animal husbandry were recruited at the year of 2001 from the same residential area as the swine farm workers'. Level of plasma IgE and 20 respiratory allergen-specific IgE were evaluated using commercially available ELISA kit. Results: Plasma IgE level was approximately five-fold higher in the swine farm workers regardless of the sampling year than the control subjects. Plant allergens from outdoor environments such as golden rod, pigweed, Russian thistle, or ragweed were the major allergens with positive reaction(allergen specific IgE${\geq}$0.7 IU/mL) for the swine farm workers at 2001 year. Meanwhile, house dust mite(Dermatophagoides farinae, D. pteronyssinus) and cockroach, typical indoor allergens in Korea, were the major respiratory allergens for the swine farm workers at 2012 year. Conclusions: Overall, even though our results are primitive, the results suggest that immunological function of swine farm workers could be modulated toward type-2 reactivity.