• Journal of Aquaculture
• /
• v.12 no.2
• /
• pp.79-89
• /
• 1999

The recombinant bovine somatotropin (rBST) was administered to the oliver flounder, Paralichthys olivaceus, to know the effects and optimal administration frequency and dosage of the hormone. The experiment was conducted with three different treatment groups (A, B and C) designated based on the duration and administration frequency of rBST and one control (D) from April 14, 1996 to March 16, 1997. The fish of hormone treated groups grew 7.86 to 10.07% (47.45 to 60.75 g in weight) better than the control at the end of the experiment (P<0.05). No significant differences in their growth were detected among treatment groups. The distinct growth improvement was recognized four weeks after completion of the first four hormone administration. When considering water temperatures measured from the experimental tanks, the effect of rBST on the flounder was greater during the period showing relatively lower temperature. The survival rates were higher in treatment groups than in the control, revealing 98.3% (A), 98.4% (B), 97.7% (C) and 93.1% (D) during the first stage of culture; 92.7% (A), 91.3% (B), 86.7% (C) and 80.0% (D) during the second stage of culture.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.1
• /
• pp.1-12
• /
• 1991

An experiment has been carefully designed and performed to verify the theory for the echointergration technique of estimating the density of fish school by the use of steel spheres in a laboratory tank. The spheres used to simulate a fish school were randomly distributed throughout the insonified volume to produce the acoustic echoes similar to those scattered from real fish schools. The backscattered echoes were measured as a function of target density at tow frequencies of 50kHz and 200kHz. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. Acoustic scattering characteristics of a 36cm mackerel was investigated by measuring fish echoes with frequencies ranging from 47.8kHz to 52.0kHz. The fluctuation of bottom echoes caused by the effects of fish-school attenuation and multiple scattering which occurred in dense aggregations of fishes was also examined by analyzing the echograms of sardine schools obtained by a 50kHz telesounder in the set-net's bagnet, and the echograms obtained by a scientific echo sounder of 50kHz in the East China Sea, respectively. The results obtained can be summarized as follows: 1. The measured and the calculated echo shapes on the steel sphere used to simulate a fish school were in close agreement. 2. The waveform and amplitude of echo signals by a mackerel without swimbladder fluctuated irregularly with the measuring frequency. 3. When a collection of 30 targets/m super(3) lied the shadow region behind another collection of 5 targets/m super(3), the mean losses in echo energy for the 30 targets/m super(3) were about -0.4dB at 50kHz and about -0.2dB at 200kHz, respectively. 4. In the echograms obtained in the East China Sea, the bottom echoes fluctuated remarkably when the dense aggregations of fish appeared between transducer and seabed. Especially, in the case of the echograms of sardine school obtained in a set-net's bagnet, the disappearance of bottom echoes and the lengthening of the echo trace by fish aggregations were observed. Then the mean density of the sardine school was estimated as 36 fish/m super(3). It suggests that when the distribution density of fishes in oceans is greater than this density, the effects of fish-school attenuation and multiple scattering must be taken into account as a possible source of error in fish abundance estimates. 5. The relationship between mean backscattering strength (, dB) and target density ($\rho$, No./m super(3)) were expressed by the equations: =-46.2+13.7 Log($\rho$) at 50kHz and =-43.9+13.4 Log($\rho$) at 200kHz. 6. The difference between the experimentally derived number and the actual number of targets gradually decreased with an increase in the target density and was within 20% when the density was 30 targets/m super(3). From these results, we concluded that when the number of targets in the insonified volume is large, the validity of the echo-integration technique of estimating the density of fish schools could be expected.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07b
• /
• pp.619-622
• /
• 2004

본 논문에서는 진화 전략 알고리즘(Evolution Strategy Algorithm)를 이용한 L1B4 선형 초음파 모터(L1B4-USM)의 최적 설계 기법을 제시하고자 한다. 유한요소법(Finite Element Method)을 정식화 하였고, 2차원 유한요소법을 L1B4-USM의 임피던스와 모드의 해석을 통해 검증 하였다. 검증된 2차원 유한 요소 해석을 통한 선형 초음파 모터의 임피던스 해석, mode 해석 및 최적 모드의 탐색 프로그램, 자동 요소분할 프로그램 그리고 진화 전략 알고리즘을 수행하였다. 이를 통해 선형 초음파 모터의 L1모드, B4 모드 각각이 발생하는 공진주파수를 일치시키며, 최대 속도를 얻기 위한 최적 설계기법을 완성 하였고, 최적화된 형상의 L1B4-USM를 설계하였다.

• Journal of the Korean Magnetics Society
• /
• v.5 no.6
• /
• pp.937-946
• /
• 1995

In this research, the processing control of NiCuZn Ferrite has been developed. The relationship between initial permeability and bulk density of NiCuZn Ferrite with processing factors was studied. NiCuZn Ferrite, which calcinated at $700^{\circ}C$ for 3 hours, was ball milled for about 60 hours to make a size of $0.5\mu\textrm{m}$ followed by granulation using spray dryer. The physical properties and the magnetic properties of NiCuZn Ferrite were investigated with the processing factor, such as (i) granule size and forming pressure, and (ii) sintering temperature. The green density of NiCuZn Ferrite was largely depended on the forming pressure rather than its granule size. The green density of NiCuZn Ferrite was increased from $2.484\;g/cm^{3}$ to $3.002\;g/cm^{3}$ with increase in forming pressure. The bulk density of NiCuZn Ferrite was increased from $3.470\;g/cm^{3}$ to $4.754\;g/cm^{3}$ linearly with increase in sintering temperature. The relationship between initial permeability and bulk density of NiCuZn Ferrite was expressed with the empirical equation,$\mu_{i}=a+b_{\rho}+c_{\rho}^2$ at forming pressure and sintering temperature.

• Journal of Life Science
• /
• v.29 no.2
• /
• pp.256-264
• /
• 2019

Lymphotoxin ${\beta}$ receptor ($LT{\beta}R$), a member of the tumor necrosis factor receptor family, plays an important role in lymphoid tissue's architecture and organogenesis. In contrast, MLCK and ROCK play critical roles in the regulation of stress fiber (SF) formation in cells. To determine whether $LT{\beta}R$ stimulation in fibroblastic reticular cells (FRCs) is involved in these signaling pathways, myosin light chain kinase inhibitor-7 (ML-7) was used to inhibit them. ML7-treated FRCs completely blocked SFs and showed retraction and shrinkage processes comparable to those observed in agonistic anti-$LT{\beta}R$ antibody-treated cells. The inhibition of ROCK activity with Y27632-induced changes in actin cytoskeleton organization and cell morphology in FRCs. Actin bundles rearranged into SFs, and phospho-myosin light chain (p-MLC) co-localized in FRCs. We checked the level of Rho-guanosine diphosphate (RhoGDP)/guanosine triphosphate (GTP) exchange activity using FRC lysate. When $LT{\beta}R$ was stimulated with agonistic anti-$LT{\beta}R$ antibodies, Rho-GDP/GTP exchange activity was markedly reduced. Regarding $LT{\beta}R$ signaling with a focus on MLCK inhibition, we showed that the phosphorylation of MLCs was reduced by $LT{\beta}R$ stimulation in FRCs. Cytoskeleton components, such as tubulin, b-actin, and phospho-ezrin proteins acting as membrane-cytoskeleton linkers, were produced in de-phosphorylation, and they reduced expression in agonistic anti-$LT{\beta}R$ antibody-treated FRCs. Collectively, the results suggested that MLCK and ROCK were simultaneously responsible for SF regulation triggered by $LT{\beta}R$ signaling in FRCs.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.1
• /
• pp.13-20
• /
• 1991

This paper describes the fish-density dependence of the mean backscattering strength with aggregations of encaged, free-swimming fish of known density in relation to the experimental verification of echo-integration technique for estimating the density of fish shoals. In this experiment, various numbers of gold crussian, Carassius burgeri burgeri, with a mean length of 18.5cm and a mean weight of 205.9g, were introduced into a net cage of approximately 0.76m super(3). During the backscattering measurements. the cage was suspended on the sound axis of the 50kHz transducer having a beam width of 33 degrees at -3dB downpoints. The volume backscattering strengths from fish aggregations were measured as a function of fish density. Data acquisition, processing and analysis were performed by means of the microcomputer-based sonar-echo processor including a FFT analyzer. The calibration of echo-sounder system was carried out at field with a steel ball bearing of 38mm in diameter having the target strength of -40.8dB. The dorsal-aspect target strengths on anesthetized specimens of gold crussian used in the cage experiment were measured and compared with the target strength predicted by the fish density-echo energy relationship for aggregations of free-swimming gold crussian in the cage. The results obtained can be summarized as follows: 1. The target strengths in the dorsal aspect on anesthetized specimens of gold crussian, with the mean length of 19.1cm and the mean weight of 210.5g, varied from -40.9dB to -44.8dB with a mean of -42.6dB. This mean target strength did not differ significantly from that predicted by the regression of echo energy on fish density of free-swimming gold crussian in the cage. It suggests that the target-strength measurements on anesthetized fish was valid and can be representative for live, free-swimming fish. 2. The relationship between mean backscattering strength(, dB) and distribution density of gold $crussian(\rho, $ fish/m super(3)) was expressed by the following equation; =-41.9+11 $Log(\rho)$ with a correlation coefficient of 0.97. This result support the existence of a linear relationship between fish density and echo energy, but suggest that this line has steeper slope than the regression by the theory of estimating the density of fish schools.

• Korean Journal of Biological Psychiatry
• /
• v.14 no.3
• /
• pp.177-183
• /
• 2007

Objectives:Previous studies have suggested that S100B protein play an important role in the pathogenesis and progress of schizophrenia. In the present study, we evaluate the serum levels of S100B in the patients with schizophrenia, and compare them with those of healthy controls. Method:The serum S100B levels were measured by lectrochemiluminescence immunoassay in 21 schizophrenic patients (8 males, 13 females) and 27 normal controls(11 males, 16 females). The Positive and Negative Syndrome Scale(PANSS) was used to evaluate the symptoms of the patients with schizophrenia, and the correlation between PANSS subscale scores and serum S100B levels was examined. Results:No significant difference was found between the serum S100B levels of the schizophrenic patients($0.074{\pm}0.039$ng/ml) and those of the normal controls($0.072{\pm}0.030$ng/ml)(p=0.925). Correlationships between the high serum S100B level with high negative symptom scores(p=0.065) or with the low positive symptom scores(p=0.080) did not exist. Conclusion:The relation between serum S100B level and schizophrenia was not found in the present study. However, to confirm this result, further studies, such as measurement of S100 protein level in CSF, postmortem study, long-term follow-up study, and studies with other neurotrophic proteins are needed.

• IMMUNE NETWORK
• /
• v.11 no.6
• /
• pp.390-398
• /
• 2011

Background: Epstein Barr virus (EBV) infected B cells are transformed into lymphoblastoid cell lines. Some researchers suggested some a few similarities between this process and carcinogenesis. We observed the expression of CD80 and CD86, co-stimulatory molecules on EBV-transformed B cells and changes of CD54 expression after stimulation of CD80 and CD86. Methods: CD80 and CD86 were stimulated using anti-CD80 and anti-CD86 monoclonal antibodies. To assess apoptosis and surface protein expression, flow cytometric analysis was performed. Intracellular signal molecules were evaluated by RT-PCR and immunoblot. Morphology and localization of proteins were examined using inverted or confocal microscope. Results: Cross-linking of CD80 and CD86 induced apoptosis and interfered with proliferation of EBV-transformed B cells, and dispersion of clumped cells. We also examined that their stimulation induced ROS accumulation and reduced CD54 expression. Interestingly, we observed that CD80 and CD86 diminished the expression of CD54 in different methods. Both CD80 and CD86 downregulated activation of focal adhesion kinase. CD80 stimulus inhibited CD54 expression through mainly RhoA inactivation, while CD86 down-regulated Ras and JNK phosphorylation. Conclusion: These results suggest that co-stimulatory CD80 and CD86 molecules, expressed EBV-transformed B cells, may play a role in apoptosis and cell adhesion.

• Korean Journal of Pharmacognosy
• /
• v.6 no.3
• /
• pp.143-147
• /
• 1975

The antifungal studies on the triterpenoids from the pericarp of Forsythia viridissima LINDL. were conducted. The pericarp was obtained from the plant which was cultivated at Eusung, Kyungsang-bukkdo, Korea. Substances A and B were isolated by column fractionation and purified by recrystallization. Antifungal actions of substance A, acetyloleanolic acid, show significant inhibition effect against Trichophyton rubrum, T. mentagrophytes, T. tonsurans, Microsporum nanum, M. canis, and M. cookei. Substance B, viridissimic acid, shows negative effect against Candida albicans and shows lower effects against other test fungi.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.1
• /
• pp.35-39
• /
• 1979

Examining the polychaetous annelids collected from the Yellow $Sea(30^{\circ}20'\;N\;Lat.\;124^{\circ}35'\;E\;Long)$ Jinhae Bay, Yeocheon Bay, Jeju Do and Weolpo. I found five species which should be added in the list as new to the polychaetous annelids fauna of Korea. In the present study five species are reported morphological descriptions. Consquently, a total 125 species of polychaetous has been reported(Kamita and Sato 1941; Paik 1972, 1973a, 1973b, 1975a, 1975b, 1976, 1977, 1978, 1979; Lee 1976; Rho and Song 1974, 1975) in Korea.