• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.1
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• pp.48-53
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• 2008

Twelve black seabreams (Acanthopagrus schlegeli) were tagged with acoustic transmitters and their movement and behavior patterns were tracked using acoustic telemetry from 12 December 2006 to 15 August 2007. Seven of the 12 fish stayed within 500 m of the release point for over a month. In the spring tide, the number of detected signals and swimming depth of tagged fish changed at 12-hour intervals with the ebb tide. The number of detected signals of tagged fish decreased dramatically with the passage of time and had decreased by over 80% in May 2007, compared with January 2007.

• Korean Journal of Microbiology
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• v.11 no.3
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• pp.129-133
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• 1973

The authors have investigated about the microbial contamination of goods which is a criterion of hygienic control. Conducting on investigation, a special attention has been paid on the rate of microbial contamination in the goods, especially in manufacturing process of the softdrink. The authors also made an experiment on total microbes which is the criterion of contamination in each step of the process and in raw materials together with materials to be used for subdividing. Results obtained were as follows : 1) The orgin of microbial contamination was found in bottle cap and in tap water, that is, there appeared 9 colony per ml in bottle cap and 31-74 colony per ml in tap water, respectively. 2) It was found that microbial contamination are 4 colony per ml in average through year. However, it appeared 1 colony per ml in winter and 8 colony per ml in summer. 3) Coliform groups are not detected in goods through a year. 4) There was no variation in number of total microbes after ion exchange resin passage in purification process of tap water. 5) The number of microbes in goods are decreased when the raw materials are treated in high temperature short time (HTST) sterilization.

• Journal of Korean Society of Forest Science
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• v.107 no.3
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• pp.287-293
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• 2018

This study was carried out to provide surface bearing capacity reinforcement of forest road by sub-base facilities based on a soft ground use of geosynthetics to prevent the damage of the road surface passing heavy logging trucks and to pass smoothly heavy truck against growing timber harvesting. The analysis of the road surface bearing capacity as progressing time and the increase of the number of passage of heavy logging trucks were conducted experimental section of forest road on the soft ground in the Forest Technology and Management Research Center. As a result, it was found that the road surface bearing capacity were stabilized at CBR of 15% or more, the effect of reinforcement by type of geosynthetics showed no significant difference after the lapse of about 1 year. After reaching the passage of 300 times for the heavy logging trucks on the sub-base construction section, the settlements was stabilized below the allowable standard of 50 mm, road surface bearing capacity also improved to more than CBR 20% and there was no significant difference in the thickness of the sub-base. However, in the section where the sub-base is not constructed, it is found that the lack of surface bearing capacity with the settlements more than the allowable standard is not possible to pass the heavy logging trucks. Therefore, in order to reinforce the road surface bearing capacity of the soft ground for the passage of the heavy logging trucks, it is necessary to construct a sub-base of at least 0.2 m when using geosynthetics.

• Journal of Life Science
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• v.18 no.3
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• pp.344-349
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• 2008

Normal somatic cells proliferate for a limited number of doublings in culture and then enter an irreversible growth-arrest state called replicative senescence. Replicative senescence has been believed a reason for the limited cellular turnover and deterioration of tissue function in aged animals. However, there is no experimental evidence supporting this assumption. Furthermore, cells from aged person have been poorly characterized with an exception of the cases of T cells. In this study, we examined cell biological changes occurring in replicative senescence of fibroblast strains originated from a new-born (NHF-NB) and a 87 year old man (NHF-87). NHF-87 (and the cells from a 75-year old) proliferated to smaller population doublings and with longer doubling times than NHF-NB did. At early passages, NHF-87 exhibited a low senescence-associated ${\beta}-Gal$ (SA ${\beta}-Gal$) activity and lipofuscin level, typical markers for cellular senescence. Furthermore, they maintained low levels of lysosome and reactive oxygen species (ROS). All of these levels increased dramatically in the late passage NHF-87 quite similarly as those in the late passaged NHF-NB did. These results indicate that most cells originated from the aged maintain a phenotype of the cells originated from new-born donors and undergo replicative senescence with the same kinetics as that of the cells from new-born. It is also indicated that not SA ${\beta}-gal$ activity but cell proliferation rate may be qualified as a biomarker for cells aged in vivo.

• Genomics & Informatics
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• v.18 no.1
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• pp.3.1-3.8
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• 2020

Patient-derived xenograft (PDX) mouse models are frequently used to test the drug efficacy in diverse types of cancer. They are known to recapitulate the patient characteristics faithfully, but a systematic survey with a large number of cases is yet missing in lung cancer. Here we report the comparison of genomic characters between mouse and patient tumor tissues in lung cancer based on exome sequencing data. We established PDX mouse models for 132 lung cancer patients and performed whole exome sequencing for trio samples of tumor-normal-xenograft tissues. Then we computed the somatic mutations and copy number variations, which were used to compare the PDX and patient tumor tissues. Genomic and histological conclusions for validity of PDX models agreed in most cases, but we observed eight (~7%) discordant cases. We further examined the changes in mutations and copy number alterations in PDX model production and passage processes, which highlighted the clonal evolution in PDX mouse models. Our study shows that the genomic characterization plays complementary roles to the histological examination in cancer studies utilizing PDX mouse models.

• The KSFM Journal of Fluid Machinery
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• v.10 no.2 s.41
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• pp.32-40
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• 2007

The present study investigated local pressure drop in a rotating smooth square duct with turning region. The duct has a hydraulic diameter $(D_h)$ of 26.7mm and a divider wall of 6.0mm or $0.225D_h$. The distance between the tip of the divider and the outer wall of the duct is $1.0D_h$. The Reynolds number (Re) based on the hydraulic diameter is kept constant at 10,000, and the rotation number (Ro) is varied from 0.0 to 0.20. The pressure coefficient distribution $(C_p)$, the friction factor (f) and the thermal performance $({\eta})$ are presented on the leading, the trailing and the outer surfaces. It is found that the curvature of the $180^{\circ}-turn$ produces Dean vortices that cause the high pressure drop in the turning region. The duct rotation results in the pressure coefficient discrepancy between the leading and trailing surfaces. That is, the high pressure values appear on the trailing surface in the first-pass and on the leading and side surfaces in the second-pass. As the rotation number increases, the pressure discrepancy enlarges. In the fuming region, a pair of the Dean vortices in the stationary case transform into one large asymmetric vortex cell, and then the pressure drop characteristics also change.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.1
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• pp.26-37
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• 1994

In this study, flow of a model intake port/valve system is analyzed by using low Reynolds number $k-{\varepsilon}$ model. Discharge coefficient was obtained from computational results for the various cases of valve lifts. Discharge coefficient becomes maximum when the valve lift is 20mm, and does not increase or decrease in proportional to valve lift. Most of pressure drop and production of turbulent kinetic energy occur at the edge points of the valve and the valve seat Thus, in order to improve discharge coefficient, rounding of edge points in valve and valve seat is recommended. As valve lift is increased, the velocity of the intake jet in the valve passage decreases, and the direction of the jet is more inclined toward the valve seat.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.1
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• pp.65-70
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• 1998

To understand the caused for poor response to superovulation in water buffalo compared to crossbred cows, follicular events, before start of superovulation, during superovulation and after superovulation were compared. Follicular development was monitored a day before start of superovulation, daily upto superestrus and on the day of flushing. A real time B mode diagnostic instrument equipped with a linear array, 5 MHz transducer was used in five crossbred cows and five Murrah buffaloes. Crossbred cows yielded significantly (p < 0.01) higher number of corpora lutea than buffaloes (21 vs 10). The mean number of small size (2 to 5 mm); medium size (6 to 9 mm) and large size $({\geq}10mm)$ follicles, a day before start of superovulation were almost similar or even slightly higher in buffalo. Though initial shift in the mean number of follicles was higher in buffalo than cow, yet, from Day 2 to Day 3 of the treatment, the average increase in medium (3.2 vs 1.2) and large size (5.0 vs 2.0) follicles was higher in cows than buffaloes. The mean number of medium and large size follicles was 9.8 and 14.4 in cows and 6.4 and 7.6 in buffaloes. On the day of flushing, the number of large size follicle was more in buffaloes than cows, indicating the ovulation problem in this species. The major conclusion from this investigation was that, a day before start of superovulatory treatment, the number of small and medium size follicles was slightly higher in buffaloes, even then superovulatory response was better in cows, due to shift, recruitment and passage of follicles from smaller size to larger size from Day 2 of treatment. Ovulation problem in buffaloes was also responsible for lower superovulatory responses as revealed by the presence of higher number of large size follicles on the day of flushing.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.711-717
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• 2007

In this study, two cell types from porcine females, namely fetal fibroblasts (pFFs) and adult ear fibroblasts (pAEFs) and two passages (3-4 and 7-8) were investigated by evaluating the development rate, blastocyst cell number and the incidence of apoptosis. No significant differences were observed in the cleavage rates of cloned and IVF embryos. The blastocyst rates between the embryos cloned with pFFs ($15.1{\pm}3.2$) and pAEFs ($10.4{\pm}2.6$) did not differ significantly but was significantly (p<0.05) lower in pAEFs than that in IVF ($22.5{\pm}4.5$) embryos. Total cell number in pFFs ($28.4{\pm}4.3$) and pAEFs cloned blastocysts ($24.2{\pm}5.1$) was significantly (p<0.05) lesser than IVF control ($35.4{\pm}3.2$). Apoptosis rates between cloned blastocysts differed significantly (p<0.05) and were significantly (p<0.05) higher than IVF embryos. The blastocyst rates between the cloned embryos cloned with different cell passages did not differ significantly but in embryos cloned with 7-8 cell passage was significantly (p<0.05) lower than the IVF control. Apoptosis signals were detected in IVF and cloned embryos as early as day 3 and the rates of apoptosis increased concurrently with the embryo development. In conclusion, high apoptosis during in vitro preimplantation development resulted in low development rate and total cell number of cloned embryos. Moreover, based on the apoptotic incidence in cloned blastocysts, fetal fibroblasts are more suitable for production of cloned embryos in porcine.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.55-73
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• 2004

The Internet is a wonderland that can be enjoyed by the young, old, and those in-between. It is also a vast commercial market where many contracts are formed every second. The Internet and E-Commerce have created new situations that have generated sweeping proposals for fundamental changes in contract law. During the first half of the 20th Century. when many businesses expanded their geographic scope, there was a tremendous desire for uniform treatment of contracts for the sale of goods throughout the U.S.A. and the whole world. That same dynamic is now occurring in E-Commerce. There is a general recognition of the desirability of uniform contract law to govern E-commerce, but to date that does not exist, though there are extensive proposals for reform of contract law on the Internet. E-Commerce is currently plagued by some of the same problems that led to the passage of the UCC. In the absence of uniform legislation, state-by-state differences are inevitable with respect to E-Commerce. State-by-state differences in E-Commerce contract law is widely viewed as undesirable. To deal with this problem, a number of uniform bills have been proposed including UCITA, UETA, and revisions to Article 2 of the UCC (Subpart B). The thrust of these uniform acts is to create legal parity between paper records and electronic records. There is considerable resistance by consumer groups to this parity and progress towards Passage of UCITA, UETA, and revised Article 2 has been slow. The UCITA covers licenses of computer software but does not cover the sale oil goods on the Internet. The scope of the UCITA includes computer software. multimedia interactive products, computer data and databases, and Internet and online information, The UETA deals comprehensively with E-Commerce and contract law. The UCC covers the sale of goods, which does not necessarily involve E-Commerce. The basic principles of contract law are modified to deal with Internet transactions. Intent is inferred from the operations of electronic agents and "signatures" can occur with a response to an invitation to click to accept.