• Korean Journal of Microbiology
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• v.42 no.3
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• pp.165-171
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• 2006

ERM proteins transfer the methyl group to $A_{2058}$ in 23S rRNA to confer the resistance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism ranging from antibiotic producers to pathogens. To define the functional role of peptide segment encompassing amino acid residues 1 to 25 in NTER (N-terminal end region) of ErmSF, one of the ERM proteins, DNA fragment encoding mutant protein deprived of that peptide was cloned and overexpressed in E. coli to obtain a purified soluble form protein to the apparent homogeneity in the yield of 12.65 mg per liter of culture. The in vitro activity of mutant protein was found to be 85% compared to wild type ErmSF, suggesting that this peptide interact with substrate to affect the enzyme activity. This diminished activity of mutant protein caused the delayed expression of antibiotic resistance in vivo, that at fIrst cells expressing mutant protein showed the retarded growth due to the antibiotic action but with time cells inhibited by antibiotic gradually recovered the viability to exert the resistance to the same extent as those with wild type protein.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.2
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• pp.154-162
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• 1992

This study was designed to investigate the antitumor effect and immunological activities of chitosan extracted from Solenocera prominetis toward on mire bearing sarcoma-180. The growth inhibition ratio of the chitosan toward sarcoma-180 showed at the highest level of 63.84% when chitosan were administrated at the concentration of 40mg/kg. The direct cytotoxic effect of chitosan was not observed in the mice bearing sar-roma-180 in vitro. In the effect of immunological activities, dose-dependent responses indicated by the increase of leucocyte, peritoneal exudate cell than that of control group when chitosan administered to the mice in the concentation of 30mg/kg and 40mg/kg. Also dose-dependent responses showed also by the increase of immunoorgans weights such as body weight, liver, spleen or thymus in the same concentration of 30mg/kg and 40mg/kg. Food pad swelling having the relationship with arthus reaction of antibody-mediated hypersensitivity and delayed type hypersensitivity was recovered the almost normal level. In the efforts of macrophge on phagocytes, there were not substantial differences in phagorytic and corrected phagocytic index. In the number of plaque forming cell(PFC), PFC on the 10$^{7}$ spleen cells were increased the levels of 18.88% and 31.83% when chitosan were adminstersd at the concentration of 30mg/kg and 40mg/kg.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.2
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• pp.166-172
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• 1997

This experiment was carried out to clarify the effect of the deep water irrigation on dry-seeded rice cultivation at the three different water managements-deep continuous flooding(DCF), water saving irrigation(WSI), ordinary irrigation(OI). The highest tillering numbers per $m^2$ of rice were 551, 466 and 455 in OI, WSI and DCF, respectively. The tillering number of rice plants were significantly reduced in DCF. Heading date was delayed and the total chlorophyll content in leaf after heading was higher in DCF than those in other irrigation methods. For the characteristics associated with lodging, the culm length in DCF was slightly elongated and the diameter of culm in DCF was thicker than that in WSI and OI. The breaking weight and bending moment in DCF also were higher than those in others. As the result, although the culm length in DCF was long, the lodging index was comparatively low. The panicle length in DCF was longer than in OI and WSI. The spikelet number per $m^2$ and 1,000-grain weight were the most in WSI, while panicle number, ripened grain ratio and grain weight were not significantly different. Longer panicle length and more spikelet number resulted in higher yielding capacity in DCF.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.4
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• pp.427-433
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• 2008

Barley Yellow Mosaic Virus (BaYMV) caused significant reduction in barley yield and is difficult to control due to alive parasitic soil-borne fungus, Palmyra gamines that transmits the, virus. Previous studies have indicated that a virus-free soil could be infested by using virus-contaminated farming machineneries and implements. For the further confirmation of this finding, different proportions of BaYMV-infested soil were mixed into virus free soil. Three barley varieties (Hordum vulgarae, cv "Olbori", "Baegdong" and "Sacheon 6") were sown in pots treated with different rate of P. graminis-infested soil ranging from 0% to 100% in October 20, 2001. Results showed that BaYMV infection increased as the rate of infested soil increased. Initial symptoms were observed in a pots treated with 10% infested soil in all the 3 varieties of barley. "Olbori" had about 5% infection in 20% infested soil and about 10% infection in 40% or 50% infested soil and about 20% infection in 60% infested soil. In "Baegdong", the trend of BYMV occurrence was similar with "Olbori" but the time of severe infection was earlier than "Olbori". BaYMV infection in "Sacheon 6" was even earlier than "Baegdong" with much more severe symptoms than "Baegdong". The growth rate of barley was affected by about 19-22% when grown in 20% infested soil. As the rate of BaYMV infested soil increased the heading date was delayed but the maturing date was early in "Olbori" and "Sacheon 6". Also, reduction rate of culm length in 3 varieties increased with increase of infested soil content. However, "Olbori" showed the highest reduction. "Sacheon 6", have been characterized with long spike length, however was significantly reduced as the infested soil increased. On the other hand, spike length of "Olbori" was not significantly affected despite of increased of infested soil. The reduction rate of 1000 kernel weight was higher in large kernel size cultivar "Sacheon 6" and "Olbori" than small kernel size "Baegdong" as increase of BaYMV-infested soil content.

• Korea journal of population studies
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• v.32 no.1
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• pp.139-164
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• 2009

The first demographic transition refers to the historical decline in mortality and fertility, as shown from the 18th Century in several European populations, and continuing present in most developing countries. The end point of the first demographic transition(FDT) was supposed to be a stationary and stable population corresponding with replacement fertility and zero population growth. In addition, households in all parts of the world would converge toward the nuclear and conjugal types, composed of married couples and their offspring. The second demographic transition(SDT), on the other hand, sees no such equilibrium as the end-point. Rather, new developments bring sub-replacement fertility, a multitude of living arrangements other than marriage, and the disconnection between marriage and procreation. Populations would face declining sizes if not complemented by new migrants. Over the last decades birth rates have been on the decline in all countries of the world, and it is estimated that already more than half of he world's population has below replacement level fertility. Measured in terms of the Total Fertility Rate (TFR), currently 34 countries have fertility levels of 1.5 or less. Similarly, Korea has been below lowest-low fertility for eight consecutive years since 2001 and below the replacement level for more than twenty years. In explaining the low fertility in Korea, some researchers explain the low fertility as revenge against a male-dominated society and institution, while others focus the impact of the employment instability. These studies share the basic ideas (spread of individualism, delayed marriage and childbearing, high divorce rate etc.) of a second demographic transition in order to explain the low fertility in Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.135-142
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• 2003

Jeju native soybean was grown at five plant densities(30${\times}$30cm, 30${\times}$25cm, 30${\times}$20cm, 30${\times}$15cm, 30${\times}$10cm) from May 11 to September 10 in 2002 in Jeju island to determine the optimum plant density. Days to flowering was delayed from 94 days to 98 days as increasing of plant density. Plant height was 103cm at 30${\times}$30cm plot, as plant density increased, was 117cm at 30${\times}$10cm plot. As plant density increased, the number of branches and leaves, stem diameter, weight of plant, root length and weight of root grew low. As plant density increased from 30${\times}$30cm to 30${\times}$15cm, fresh forage, dry matter, crude protein and TDN yield increased 23.3∼36.5MT/ha, 5.1∼8.0MT/ha, 0.8∼1.4MT/ha and 2.9∼4.8MT/ha respectively, but decreased at 30${\times}$10cm plot. As plant density increased, crude protein, crude fat, NFE and TDN content increased 16.2∼17.9%, 2.7∼3.7%, 37.6∼40.7% and 56.1∼60.0% respectively. In contrast with this, crude fiber and crude ash decreased 34.9 ∼30.8% and 8.6∼7.2% respectively. To reach the climax of forage yield was estimated optimum plant density to be 30${\times}$15cm.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.106-113
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• 2009

Germination percentage of Korean native lily seeds was high at $20-25^{\circ}C$. It was almost 100% in L. cernuum, L. callosum, L. amabile, and L. concolor, 88.0% in L. lancifolium, and 73.0% in L. maximowitzii, respectively. Meanwhile, it was low rate of 34.0%-54.0% in L. distichum, L. hansonii, and L. tsingtauense. Germination was mostly delayed of $15^{\circ}C$ and days to germination were more shortened in species with higher germination percentage. Even though the effect of daylength was not considerable in germination rate, it was promoted in L. maximowitzii but it was delyed in L. hansonii under long day. The effect of soaking in hot PGRs solution in L. callosum, L. cernuum, L. amabile, L. lancifolium, and L. concolor did not show any difference in comparison with non-treatment. However, it was improved by BA in L. maximowitzii. Longer period of cold wet storage resulted in improved germination percentage in L. maximowitzii and L. lancifolium, while it affected decreased percentage in L. distichum and L. hansonii. Days to germination were shortened by longer period of cold wet storage regardless of species. Germination percentage in dry storage was higher under cold temperature than room temperature and under desiccator storage than outside desiccator, it was highest under desiccator storage at $4^{\circ}C$. It was drastically reduced by the non-use desiccator storage at room temperature L. concolor, however it was improved only by the use of desiccator L. maximowitzii for a long time.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.157-164
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• 2010

In Chrysanthemum ${\times}$ morifolium, 30 days of continuous short days (SD) are required for flowering. The effects of alternating short day (SD) - long day (LD) - SD treatments was tested in 5 daisy-like single cultivars, 'Limelight', 'Sunlight', 'Candle Light', 'Firebrand', and 'Twilight', Thee other decorative type cultivars, 'Spirit', 'SunburstSpriit', 'Mandalay', and 'Illini Harvest' was also included. Short day treatment was given for 30 days (control: 30SD) and 5 or 10 LD were interposed following 5 or 10 SD. Different responses were noticed when data from all cultivars were combined, showing that flowering was delayed and the number of ray florets were increased by 5 SD-10 LD-25 SD. The number of ray florets, 40 florets in 'Firebrand' and 60.8 florets in 'Candlelight' was increased significantly by 5 SD-10 LD-25 SD as compared to the control. There were no adverse effects by SD-LD-SD treatment, except for the delay in flowering time from 6 to 7 days. The number of ray florets in 'Illini Harvest' and 'Limelight' were, however, not increased by any SD-LD-SD treatments. Cultivar dependent responses should further be investigated in other newly available cultivars, and this information could be used to breed new cultivars.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.1
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• pp.73-83
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• 2015

Dendropanax morbifera Leveille (Araliaceae) is an endemic species growing in the south-western part of South Korea and has been used in folk medicine. However, the effects of Dendropanax morbifera Lev. on skin biology remain to be elucidated. In this study, we isolated 1-tetradecanol and ${\beta}$-sitosterol from the n-hexane fraction of Dendropanax mobifera Lev. and To investigate the whitening effect of the fraction, we tested the inhibition of tyrosinase activity of 1-tetradecanol. The results show that the inhibitory effect of the 1-tetradecanol was higher than water extract and n-hexane fraction. And 1-tetradecanol significantly reduced melanin contents of B16F10 cells compared to more than water extract and n-haxane fraction dose-dependantly without cell cytotoxicitiy (below $100{\mu}g/mL$). We also investigated the skin moisturizing effect using HR-1 hairless mice. The transepidermal water loss (TEWL) in the 1-tetradecanol treated group was significantly smaller than that in the other groups. To investigate the effect of the preventing hair loss by ${\beta}$-sitosterol, we observed HR-1 hairless mice through periodic growth feature. The results suggest that hair loss of mice by ${\beta}$-sitosterol was delayed and it's hair density showed the highest. These data provide evidence that Dendropanax morbifera Lev. may be a potent candidate for the improvement of both skin whitening, moisturizing and alopecia from the point of cosmetic industry view.

• Food Science and Preservation
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• v.18 no.3
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• pp.288-293
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• 2011

This study investigated the changes in the quality of fresh-cut lotus roots that were treated with hot water. Lotus roots were purchased from Daegu, Korea. They were washed, peeled, and cut into lcm-thick slices with a ceramic knife. The peeled and sliced lotus roots were dipped for 45 sec in water at 30, 55, and $80^{\circ}C$. After they were air-dried at room temperature, the slices were packed in polyethylene films and stored at $4^{\circ}C$ for 12 d. Then the changes in the weight loss, color, total viable cell, and sensory characteristics were measured. Generally, the weight loss of the lotus roots that were treated with hot water slightly increased. The application of the heat treatment delayed the browning of the lotus roots, especially the treatment with $55^{\circ}C$ hot water. The L and a values of the lotus roots that were treated with $80^{\circ}C$ hot water significantly increased during their storage, though. The heat treatment effectively inhibited the growth of microorganisms. The organoleptic quality of the lotus roots that were treated with $55^{\circ}C$ hot water was the best.