• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.161-167
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• 2011

The soil moisture has an important effect on growth and development of highbush blueberry (HB), mainly because the root system, devoid of root hairs, is superficial. Moreover, the texture and organic matter content of Korean soil is different from the main producing counties, such as USA and Canada. To facilitate the growth and development of HB and long-term maintenance of productivity, the research related to soil moisture condition in Korea should be the priority. This study was performed to investigate the growth properties of the HB in various soil moisture conditions in order to determine the irrigation trigger point and optimum soil water potential. The texture of soil used in this experiment was loam. For the experiments, the soil was mixed with peatmoss at a rates 30% (v/v). Irrigation was scheduled at -3, -4, -5, -8, -15 and -22 kPa soil water potential then investigated leaf macronutrient, bush growth, and fruit properties. The leaf K content of HB showed the same trend in the soil water potential, but Leaf P and Mg content was highest in -5 and -22 kPa, respectively. The productivity and growth amount of HB showed the peak at the range of -4~-8 kPa as normal distribution pattern, and greatly decreased at above -15 kPa. Total dry weight and Cane diameter were highest at -4 kPa, plant width, fruit weight and yield were highest at -5 kPa, and plant height, cane number and shoot tension were highest at -8 kPa. Soluble solids content showed same trend in the soil water potential, but titratable acidity, anthocyanins and total polyphenols were not significantly different. Therefore, the optimal soil water potential for the development and a maximum production of HB were a range of -4~-8 kPa, and the recommended ideal irrigation trigger point was within -15 kPa.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.484-489
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• 2010

The cultivation of green manure crops plays an important role in soil quality and sustainability of agricultural system. However, the incorporation of green manure crops may be of concern because it can lead to strongly reducing conditions in the submerged soil. This study was conducted to evaluate the effects of rice husk carbon on rice (Oryza sativa L.) cultivation using green manure mixtures (hairy vetch + rye) in rice paddy. Field experiments were conducted in rice paddy soil (Shinheung series, fine loamy, mixed, nonacid, mesic family of Aeric Fluventic Haplaquepts) at the National Institute of Crop Science (NICS), Korea from October 2007 to October 2008. The experiments consisted of three treatments: application or no application of carbonized rice husk, and conventional fertilization. These treatments were subdivided into whole incorporation and aboveground removal of green manure mixtures. The redox potential (Eh) was higher upon application of the carbonized rice husk when compared to no application at 8 and 37 days after transplanting (DAT). The ammonium-N ($NH_4$-N) in soil was highest upon the application of carbonized rice husk + whole green manure incorporation at 17 and 49 DAT. Plant height and tiller number of rice were similar to the $NH_4$-N concentration in soil. Rice yields of application and no application of carbonized rice husk treatment were not significant. However, application of carbonized rice husk improved the soil physical properties such as bulk density and porosity after rice harvest. Therefore, the results of this study suggest that carbonized rice husk could be used as soil amendment for environmentally-friendly rice production under a green manure mixture-rice cropping system.

• Food Science and Preservation
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• v.16 no.2
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• pp.276-285
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• 2009

This study evaluated the microbiological quality and safety of food items(seafood, meat, eggs, and frozen food) supplied to elementary school food services, during delivery, and analyzed the distribution/delivery system. To this end, 10 food items supplied by 13 factories in Daegu and Gyeongbuk were chosen for study. Beef and pork were delivered directly to schools in freezer vans. Seafood, chicken, and frozen food were delivered to schools by refrigerated vans(${\leq}10^{\circ}C$) that made other delivery stops before arriving at schools. After food was delivered to schools, total bacterial counts and coliforms(respectively) were as follows: mackerel($2.0{\times}10^2-3.2{\times}10^5$, $<5-4.0{\times}10^3CFU/g$), common squid($2.5{\times}10^4-6.6{\times}10^5$, $1.6{\times}10^2-6.0{\times}10^3CFU/g$), shellfish($3.2{\times}10^5-1.7{\times}10^3$, $4.0{\times}10^3-3.0{\times}10\;CFU/g$), boiled fish paste($1.9{\times}10^4$, <5 CFU/g), beef($9.2{\times}10^2-6.4{\times}10^4$, $<5-2.0{\times}10\;CFU/g$), pork($2.6{\times}10^3-1.3{\times}10^6$, $<5-2.7{\times}10^2CFU/g$), chicken($1.0{\times}10^4$, $2.4{\times}10^2CFU/g$), egg($<5-2.3{\times}10^2$, <5 CFU/g), frozen mandu($3.2{\times}10^3-9.5{\times}10^4$, <5 CFU/g), and frozen noodles($<5-9.0{\times}10$, <5 CFU/g). Bacillus cereus($2.0{\times}10\;CFU/g$) and E. coli($1.0{\times}10\;CFU/g$) were detected on shellfish, and Staphylococcus aureuswas detected on pork($3.1{\times}10\;CFU/g$) and chicken($7.8{\times}10\;CFU/g$). Most food items were double-wrapped in vinyl and placed in corrugated cardboard boxes prior to delivery, and the boxes weremixed with other food items when they were put in the vans. There was no cross-contamination during distribution. However, total shellfish bacterial counts increased slightly. These results indicate that foods need to be completely pasteurized during processing. Frozen food items should not be mixed and should be delivered by freezer vans(${\leq}4^{\circ}C$). The number of stops made during distribution/delivery should be reduced.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.109-115
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• 2012

Helicobacter pylori is an important factor of chronic gastritis, digestive ulcer, and stomach cancer. CagL, a virulence factor of H. pylori, is well-known as a pilus protein which acts as adhesion to host cell and a component of Type 4 secretion system. In this study, we evaluated the protective response of recombinant CagL protein (rCagL) using Mongolian gerbil animal model for H. pylori infection. The cagL gene was cloned from 26695 H. pylori followed by over-expression and purification of the protein in E. coli. Mongolian gerbils were immunized with rCagL protein mixed with aluminum adjuvant via intramuscular injections once a week during 4 weeks. At a week after the last immunization, the Mongolian gerbils were administrated with H. pylori 7.13 strain into the stomach and sacrificed to measure antibody titer on rCagL by ELISA and bacterial colonization in the stomach, and to examine the histopathological changes and cytokine expression at 6 week after challenge. Antibody titers on recombinant protein were significantly increased from a week after the first immunization. There was no significant change of the number of bacterial colony between control group and immunized group. The relative stomach weight was significantly decreased in immunized group, but the significant change of histopathological assessment was not observed in the stomach. Cytokine expression such as IL-$1{\beta}$ and KC also was not significantly different between control and immunized groups. These results indicate that rCagL could effectively induce the formation of the specific IgG antibodies. However, bacterial colonization and histopathological lesions could not be inhibited by the immunization in the stomach, indicating not enough protection against H. pylori infection. We consider that along with CagL other adequate antigens could be needed stimulating immune response and inducing protective effects against gastric disease, and also a better adjuvant could be considered.

• Journal of the Korean Geographical Society
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• v.28 no.3
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• pp.213-226
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• 1993

In Korea, the urban studies of geography have mainly dealt with such a series of research as system of urban place and internal structure of urban area. The existing studies have been carried out with ecological approach. Ecologists, now a days, regard organiation and transfor-mation of the urban space as the process of invasion, succession, and segregation. However it is more proper that cities should be considered not as fragmantary objects, as some ecologists insist, but as synthetic ones in social structure. This research, with adopting a case of the renewasl of central area in Seoul, tried to make it clear that the formation and transition of the city is a product of social structure and examined polical and economic logic which exists in variation of urban space in detail. The results of this study are as follows; Urban renewal of central area is closely related with production and reproduction in capitalist society. In urban center, as business activities had increased since 1973 due to decen-tralization of production process, the necessity of reorganizing the land use in existing central area accordingly increased. The urban renewal program of central area in Seoul was inrroduced under such situation. The urban renewal of central area reflecting the capital logic has changed the central area with six hundred year's tradition. From the urban renewal of central area, not only was the central area, which traditionally had been mixed with various fun-ctions, simplified into the unitary area of busi-ness, but also physical landscape changed. As the land lot in renewal area expanded into regular shape, buildings became larger and taller. The program tremendously raised the price of related area. Aiming at these profits caused by the raised price, a great number of capitalists participated in the program. And as the benefit ratio of the manufacture sector continuously dropped with the economic recession, the pro-gram was carried out much more vigorously. That was because the idle capital accumulated during the recession was invested in property sector and was self-proliferated. The urban renewal raised the land value of central area and drove out the people living in this area. The people moved into the whole parts of the city resulting diffused squatter settlements. And the urban changes in central area were results of the policy of municipal authorities, who supported and systematized the changes lawfully and administratively, as well as reali-zation of capital logic. Due to the renewal policies of central area in Seoul, much more renewals by the only capitalists were carried out than those by the people themselves living in that area. The integration of land ownership in the law of urban renewal shows the reason of that. Moreover, the law allows the third deve-loper to participate in the tasks and admits the land expropriation rights. The municipal autho-rities guaranteed the profitability of the tasks through finacial aid, tax benifit, and relaxation of regulations for construction. As examined above, the changes in the land use of urban space have been led not by the ecological process of development of the city itself, but by the restructuring of capitalism and the intervention of the government authorities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.8
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• pp.992-997
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• 2008

In this study, we investigated the indirect effect of silk-fibroin on osteoclastic differentiation of RAW264.7 cells. The conditioned medium were collected from MC3T3-E1 osbeoblasts treated with $0.001\;mg/mL{\sim}0.1\;mg/mL$ silk fibroin for 6 days, mixed in 1:1 ratio with osteoclast medium, and then added into RAW264.7 cells with receptor activator of nuclear factor kappa B ligand (RANKL), a differentiation inducer for 3 days. Of osteoclastic cytokines in the conditioned medium, the protein expression of osteoprotegerin (OPG) with silk-fibroin was not significantly different. However, the protein expression of interleukin (IL)-$1{\beta}$ was specifically lower in a dose dependent manner. In RAW264.7 cells, the conditioned medium with silk-fibroin inhibited RANKL induced osteoclastic differentiation as total number of multinucleated tartrate-resistant alkaline phosphatase (TRAP)-positive osteoclasts in a dose dependent manner. Taken together, we demonstrated that the conditioned medium of silk-fibroin treated osteoblasts inhibits RANKL induced differentiation of osteoclasts with inhibiting selective expression of IL-$1{\beta}$.

• Journal of Aquaculture
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• v.13 no.4
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• pp.277-284
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• 2000

Rabbitfish hatchlings were given a mixed food of rotifers (Brachionus rotundiformis) and trochophore larvae of oyster. Only the oyster-trochophore larvae were found in the gut of 62-h old fish larvae. The fish larvae, fed on rotifer and ciliate alone did not survive. However, their survival increased to 3.3 % on the 10th day after hatching, when trochophore was supplemented. Corresponding with the accelerated growth, the number of rotifers consumed increased from 11 in a 5-day old fish to 165 in a IS-day old fish. In a field ecosystem containing live diatom, Nannochloropsis oculata, rotifers and copepods, fish larvae were shocked and the oyster's trochophore larvae were fed from 2 to 7 days after hatching. A total of 76,000 seedling were produced after 50 days of hatching with 12.7 % survival. Mean total length and body weight were 65.6 mm and 3.4 g, respectively. Growth of body length (BL), body height (BH), body weight (BW) and head length (HL) as a function of the total length (TL) showed regressional relationships as follows; BL=0.8565 TL+0.0852 ($t^2$=0.9996); BH=0.3207 TL - 0.5052 (($t^2$=0.9641) BW=0.0652 TL2.3508 (($t^2$=0.9925); HL=0.2595 TL - 0.1898 (($t^2$=0.9901)

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.71-94
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• 2020

Korea's innovation cluster policy has been implemented since 2005 with the goal of balanced regional development. The purpose of this study is to investigate the factors affecting the sustainability of innovative cluster tenants by using Pangyo Techno Valley as an example. Pangyo Techno Valley was established under the leadership of the local government (Gyeonggi-do) rather than the central government and it is called "Silicon Valley of Korea" and "Asia Silicon Valley" and is becoming more representative. The growing number of companies in Pangyo Techno Valley decreased in 2017 compared to 2016. This is because Pangyo Techno Valley's business ecosystem will change from 2019. In this paper, quantitative and qualitative studies were conducted to investigate the influencing factors. Quantitative research was conducted based on the survey and qualitative research was applied through interviews. The quantitative research examined the factors affecting the sustainability of Pangyo Techno Valley, and the qualitative research examined the specific reasons and additional factors for the quantitative research results. The quantitative results showed that factors affecting sustainability in terms of changes in corporate internal conditions, human and physical infrastructure, cooperation and synergy, and occupancy patterns. The specific reason for the impact appeared in the qualitative research process. The support category of local governments did not show any significant factors in quantitative research. In addition, qualitative research suggested 'Good image of Pangyo Techno Valley' as the category that has the greatest impact on sustainability. It is shown that companies are passive and expect the role of local governments in activating cooperation network in Pangyo Techno Valley. In this paper, based on the results of the study, Pangyo Techno Valley is presented with a realistic plan based on real estate issues and an ideal plan with a long-term perspective.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.77-82
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• 2014

The present study was conducted to establish an effect and a proper concentration for treatment with gibberellic acid ($GA_3$) and thidiazuron (TDZ), resulting with increase berry size and yield in Gaeryangmeoru grapes. Berry size was increased by treatment with $GA_3$, and the fruit clusters obtained for the groups treated with $GA_3$ concentrations of 100 and $200mg{\cdot}L^{-1}$ were bigger. The berry number was also enhanced in $GA_3$ treated groups, but the soluble solid content and acidity was not significantly different. Damage caused by $GA_3$ treatment, such as peel pollination and berry shatter, was observed in the group with $200mg{\cdot}L^{-1}$. The berry size was larger in group treated with a high concentration of $GA_3$ and TDZ respectively than in those treated with low concentrations in the treatment mixed $GA_3$ and TDZ; however, fruit with low soluble solid content and high acidity was harvested after $GA_3$ and TDZ treatment due to delay of berry ripening. The pericarp tissue layers were not changed, but the distance from the epidermis layer to vascular bundle tissue was increased as a result of $GA_3$ and TDZ treatment. Therefore, $GA_3$ and TDZ did not affect an cell division but not cell size, resulting in an enlarged berry size. It is necessary to treat plant growth regulators 2~3 times and immediately after berry set to enhance berry set rate, because the period of berry set is short. This study suggests that the proper concentration for enhancing berry size and set were up to $100mg{\cdot}L^1$ $GA_3$ or $50mg{\cdot}L^{-1}GA_3+1.25mg{\cdot}L^{-1}$ TDZ, and it is necessary to pay attention to harvest mature fruits because of the delay of ripening caused by the usage of TDZ.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.418-423
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• 2017

In hydroponics, the nutrient solution is supplied considering the water and nutrient uptake characteristics of crops. However, as the ionic uptake characteristics are changed as a result of the weather conditions or the growth response of the crops, the root zone can not be maintained in optimal condition. In addition, the coir substrate has been used mainly for the tomato cultivation in place of the inorganic substrate, there are few studies on long-term cultivation using coir substrate. Therefore, this study was conducted to investigate the effect of EC level of irrigation solution on tomato growth and inorganic ions of root zone in soilless culture using coir. Coir substrate mixed with 5 : 5 chip and dust was used. EC level of irrigation solution was 1.0, 1.5, 2.0, and $3.0dS{\cdot}m^{-1}$. At the initial stage, $NO_3-N$, P, Ca and Mg in the drainage were lower than the irrigation level at 1.0 and $1.5dS{\cdot}m^{-1}$. However, EC $2.0dS{\cdot}m^{-1}$ or higher, all the ions except P were highly concentrated in the drainage. The average fruit weight was not significantly different between 1.0 and $1.5dS{\cdot}m^{-1}$ until 3th cluster, but from the next cluster, the higher the EC level, the smaller the weight. The number of fruit and yield to 6th cluster was the highest at $1.5dS{\cdot}m^{-1}$. From the next cluster, The yield was decreased with the higher EC level. At the early stage of growth, BER occurred only in EC $3.0dS{\cdot}m^{-1}$, but increased in all treatments with increasing irradiation. The incidence rate of EC $3.0dS{\cdot}m^{-1}$ was higher than that of the lower EC level treatment.