• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.1
• /
• pp.11-18
• /
• 2008

Human bone marrow mesenchymal stem cells are thought to be multipotent cells, which are present in adult marrow, that can replicate as undifferentiated cells and that have the potential to differentiate to lineages of mesenchymal tissues, including bone, cartilage, fat, tenden, muscle, and marrow stroma. Cells that have the characteristics of human mesenchymal stem cells could be isolated from marrow aspirates of human and animals. This study was designed to identify and characterize genes specifically expressed by osteogenic supplements -treated cells by suppression subtractive hybridization(SSH) method. The results were as follows: 1. 2 genes were upregulated genes in osteogenic diffeentiation of hMSCs, which is further proved by Northern blot analysis. 2. IGFBP-2 has been identified playing an important role in bone formation. 3. HF1 was also upregulated during osteogenic differentiation, but its role in bone formation is not clear yet.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.8 no.1
• /
• pp.145-154
• /
• 2002

Purpose : The purpose of this study was to investigate the experiences of masturbation among high school students. Method : The subjects were 925 high school students in Busan. Masturbation experience, hygienic management and physical, psychological condition after masturbation were measured. The data was collected from December 1998 to February 1999. The collected data was analyzed with frequency, percentage, mean, $x^2$ -test, t-test. Result : 1) There were significant differences in masturbation experiences according to frequency($x^2$=547.94, p=.000), educational participation($x^2$=12.11 p=.001) and hygienic management(t=3.661, p=.001) between boys and girls. 2) Contact of lewd mass media stimulated students to do masturbation and they used various methods such as stimulating genital area by using hand or tools, fantasizing about sex 3) Subjects reported that they experienced fatigue, sleeping disturbance, decreasing concentration and learning desire after masturbation. Conclusion : This study suggests that replicate studies are needed. The results are also useful in developing various sex education program.

• Journal of Aquaculture
• /
• v.13 no.1
• /
• pp.29-37
• /
• 2000

In previously study we isolated several fish matrix attachment regions (MARs) capable of replicating the plasmid by itself. In this study we construct a fish expression vector pBaEGFP(+) containing mud loach ${\beta}$-actin promoter EGFP as reporter gene and SV40 signal. To analyze the effects of the fish expression vector respectively. The fish ARS containing constructs pBaEGFP(+)-ARSs were transfected cells with pBaEGFP(+)-ARS101 and pBaEGFP(+)-ARS223 reduced 10 days to 25 days and then was constant to 30 days after transfection while that of the control vector without ARS element was basal level. The intensity of both constructs showed about 30fold of the intensity compared with the control vector on 30days after transfection individually .E. coli back-transformation analysis shows that pBaEGFP(+)-ARS223 and pBaEGFP(+)-ARS905 maintain in episomal state at least 30 days after transfection. The result indicates that both may be able to replicate the vector in BF-2 cell. Therefore the matrix-attached ARSs enhancing expression of the reporter gene might be useful as a component o the expression vector for transgenic studies.

• ALGAE
• /
• v.23 no.4
• /
• pp.289-294
• /
• 2008

To estimate seaweed biomass or standing crop, a nondestructive sampling can be beneficial because of not much destroying living plants and saving time in field works. We suggest a methodological procedure to estimate seaweed biomass per unit area in marine benthic habitats by using species-specific regression equations. Percent cover data are required from the field samplings for most species to convert them to weight data. However, for tall macroalgae such as kelps we need density data and their size (e.g., size class for subtidal kelps) of individuals. We propose that the field sampling should be done with 5 replicates of 50 cm x 50 cm quadrat at three zones of intertidals (upper, middle, lower) and three depth points (1, 5, 10 m) in subtidals. To obtain a reliable regression equation for a species, a substantial number of replicate is necessary from destructive samplings. The regression equation of a species can be further specified by different locality and different season, especially for the species with variable morphology temporally and spatially. Example estimation carried out in Onpyung, Jeju Island, Korea is provided to compare estimated values with real weight data.

• Journal of Korea Water Resources Association
• /
• v.31 no.5
• /
• pp.613-620
• /
• 1998

Field and laboratory studies of the near field behavior of the San Francisco ocean outfall were reported. The data sets cover broad ranges of discharge conditions and oceanic conditions, and are associated with a typical type of outfall discharges with multiport diffusers. The laboratory data sets were obtained in density-stratified towing tanks to replicate the field tests. Model studies of wastefield behavior using these data sets were predicted by the mathematical models UM, UDKHDEN, RSB, and CORMIX2 for minimum dilution, the height to top of wastefield, and wastefield thickness. In this paper, the results are discussed and compared measurements with mathematical model predictions. The hydraulic model studies reproduced the major features observed in the field. It also afforded considerable insight into the mechanics of mixing of multiport risers which could have been obtained neither from the field test nor the mathematical models.

• Korean Journal of Poultry Science
• /
• v.47 no.3
• /
• pp.135-142
• /
• 2020

The objective of this experiment was to determine the apparent (AID) and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in five feed ingredients for male broiler chickens (Ross 308). The test feed ingredients consisted of corn, wheat, soybean meal (SBM), canola meal (CM), and corn distillers dried grains with solubles (DDGS). The birds were fed a standard starter diet for the first 19 d. On day 19, nine hundred sixty birds were assigned to six dietary treatments with eight replicate cages (20 birds/cage) in a randomized complete block design. All experimental diets contained chromic oxide (0.5% in the diet) as an indigestible index. The diets were offered ad libitum for 4 d. At the end of the experiment, all birds were euthanized and ileal digesta samples were collected immediately. The indispensable AA with the least AID and SID were Thr for all the ingredients used in the present study, except for DDGS, in which Lys had the lowest digestibility. For indispensable AA, the AID and SID of Leu, Phe, Arg, and Met were the greatest in corn, DDGS, wheat, SBM, and CM, respectively. The results from the present study showed that there are variations in both the AID and SID of CP and AA among feed ingredients.

• Journal of Plant Biology
• /
• v.26 no.3
• /
• pp.161-171
• /
• 1983

To test whether the Grime's model on relationship between maximum standing crop plus litter (350~750g/$m^2$) and species density (10~30/0.25$m^2$) fit well or not, a total of 52 samples, with 4 replicate plots (0.5m$\times$0.5m each) per sample, was collected from various forests, grass lands and coastal salt marshes in midwestern part of central Korean peninsula from September to October in 1982. The result agrees well with the model for grass lands salt marshes, that is, shape of curve for the maximum standing crop (minus litter) against species density indicates normal distribution. The number of species was 11 for the grassland and 7 for the salt marshes within the range of 300g to 700g per square meter for the maximum standing crop. In forest stands, however, as the maximum standing crop of herbs increased the species density decreased. The Grime's model does not seem to fit with the resutls on forest stands of this study. It is examined further the relationships among the maximum standing crop, species density and eleven soil properties, and the possible cause of this discrepancy was disscused.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.10a
• /
• pp.162-165
• /
• 2007

AAO(Anodic Aluminum Oxidation) method has been known that it is practically useful for the fabrication of nano-structures and makes it possible to fabricate the highly ordered nano masters on large surface and even on the 2.5 or 3D surface at low cost comparing to the expensive e-beam lithography or the conventional silicon processing. In this study, by using the multi-step anodizing and etching processes, highly ordered nano patterned master with concave shapes was fabricated. By varying the processing parameters, such as initial matter and chemical conditions; electrical and thermal conditions; time scheduling; and so on, the size and the pitch of the nano pattern can be controlled. Consequently, various alumina/aluminum nano structures can be easily available in any size and shape by optimized anodic oxidation in various aqueous acids. In order to replicate nano patterned master, the resulting good filled uniform nano molded structure through electro-forming process shows the validity of the fabricated nano pattern masters.

• Korean System Dynamics Review
• /
• v.9 no.1
• /
• pp.57-71
• /
• 2008

This research paper describes a complex and vague settings in which organization makes a decision and explains a role of decision maker's learning process. The original paper, written by Cohen, March, Olsen in 1972, said that all members of organization depended on the technology taken through trials and errors, which is the 'learning' process literally. But they intended to exclude the learning process in their simulation model because their PORTRAN model couldn't replicate the learning concept. As a result, they couldn't explain how all agents of garbage can simulation model resolve the problem dynamically. To overcome this original paper's limitations, we try to rebuild a learning process simulation model using by system dynamics approach that can capture the linkage between organization leanings and agents-based decision-makings. Our learning simulation results reveal two points. First, decision maker's leanings process improves the efficiency of decision making in complex situation. Second, group learning shows a superior efficiency to an individual learning because group members share organizational memory and energy.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.1
• /
• pp.1-6
• /
• 2001

Ten strains of plasmid-harboring Bifidobacterium sp. were isolated from the feces of adults and children, and named as Bifidobacterium sp. GE1-GE8, ST, and SH5. These plasmids were categorized into three homologous groups (pKJ50-homologous, pKJ36-homologous, and non-homologous groups) according to Southern hybridization patterns using the formerly characterized bifidobacterial plasmids, pKJ50 and pKJ36, as probes. nine strains harboring the plasmids were shown to accumulate single-stranded DNA as a replication intermediate, based on the S1 nuclease treatment and Southern hybridization. These results suggest that the strains replicate by a rolling circle mechanism. Minimal inhibitory concentrations (MIC) of the isolated bifidobacteria against several antibiotics were determined. Two strains, GE2 and GE3, showed relatively high MiC values against tetracycline ($793.6{\mu}g/ml$) and erythromycin ($153.6{\mu}g/ml$), respectively. The tetracycline resistance of GE2 disappeared when the resident plasmid of GE2 was cured by ethidium bromide. These results show that pKJ36-homologous and pKJ50-homologous plasmids are prevalent among various Bifidobacterium strains and some Bifidobacterium plasmids appear to code for antibiotic resistance.