• Mass Spectrometry Letters
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• v.2 no.2
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• pp.33-36
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• 2011

The misuse of anabolic androgenic steroids is of particular concern in sports and society. Thus, it is of great importance to discriminate endogenous steroids such as testosterone or testosterone prohormones from their chemically identical synthetic copies. In this study, gas chromatography-combustion/isotope ratio mass spectrometric (GC-C/IRMS) method has been developed and validated for discriminating the origin of anabolic androgenic steroids. The method involves the solid-phase extraction, enzymatic hydrolysis with ${\beta}$-glucuronidase, HPLC-fractionation for the cleanup and analysis by GC-C/IRMS. The difference(${\Delta}^{13}C$) of urinary ${\delta}^{13}C$ values between synthetic analogues and endogenous reference compounds (ERC) by GC-C/IRMS was used to elucidate the origin of steroids, and intra- and inter-day precision, specificity and isotope fractionation were evaluated. The present GC-C/IRMS method combined with HPLC cleanup was accurate and reproducible enough to be successfully applied to the test of urine sample from suspected anabolic steroid abusers.

• Environmental and Resource Economics Review
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• v.19 no.4
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• pp.805-828
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• 2010

Korea also plans to introduce Renewable Portfolio Standard (RPS) for strengthening market functions after 2012 as United States and several members of EU countries did. Through the introduction of RPS, it requires energy industry to supply new and renewable energy at fixed rate. Therefore, it will contribute to the distribution of new and renewable energy. This paper analyzed the economic effect of the introduction of RPS using CGE. The summary of the paper on the analysis of the economic effect based on endogenous growth theory under imperfect market competition by using CGE is as follows; Since RPS possibly regulates the amount of new and renewable energy, it can achieve the target amount of new and renewable energy without fail. As achieving the target amount accurately, the distribution of more advanced skills can be expected. However, GDP reduction can occur because investment cost increases due to the requirement of new and renewable energy supply. Therefore, in the long run, it is appropriate to introduce RPS because it contributes to the distribution of new and renewable energy and can be utilized as a new growth engine to encourage economic growth.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.223-226
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• 2008

Seedlings of two rice cultivars i.e. cv. Daesanbyeo and cv. Dongjinbyeo were analyzed for growth and endogenous gibberellins (GAs) in response to nitrogen nutrition applied in the forms of $KNO_3$, $(NH_4)_2SO_4$ and $NH_4NO_3$. All the growth parameters showed an increase in N applied treatments and their magnitudes of increase were different depending on different nitrogen fertilizer forms. The endogenous GAs contents were increased with N application but differentially affected by various N-forms in both rice cultivars. In cv. Daesanbyeo, maximum amount of bioactive $GA_1$ was recorded for $(NH_4)_2SO_4$, while maximum amount of bioactive $GA_1$ in cv. Dongjinbyeo was observed in $NH_4NO_3$ applied treatments. In both rice cultivars, $KNO_3$ applied rice plants contained least $GA_1$ contents. Also, $GA_{19}$ was the most abundant GA found in rice seedlings whereas $GA_4$ was absent at seedling stage. Our study indicated that different rice cultivars showed different responses for the same fertilizer depending upon the response potential of each cultivar and the pertinent physiological responses to changes of endogenous GAs in rice cultivars, which were comparatively lesser in magnitude.

• Clean Technology
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• v.8 no.2
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• pp.77-83
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• 2002

The purpose of this study is to develop the efficient nutrient removal process and to verify operation and design parameters in domestic sewage. Endogenous nitrate respiration (ENR) was used for denitrification of nitrate in return sludge without additional organic carbon source. ENR reactor before the anaerobic tank enable to reduce nitrate below 3 mg/L and increase phosphate release at anaerobic reaction. Primary effluent during pilot scale plant were shown as TCOD/TP ratio of 40~60 and TCOD/TKN ratio of 5~7. Effluent concentrations were 10 to 12mg/L as TN and 1mg/L as TP respectively. In lab scale experiments endogenous denitrification rate of ENR reactor ranges from 0.042 to $0.057gNO_3-N/gMv.d.$ $SP_{rel}/SCOD_{rm}$ was shown as from 0.13 to 0.17 in anaerobic reaction. These kinetic parameters are expected to be available for BNR(Biological Nutrient Removal) plant design and ENR reaction is available for nutrient removal in low strength wastewater.

• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.269-275
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• 1998

Spider crabs, Libinia emarginata, were eyestalk-ablated unilaterally and bilaterally to manipulate endogenous methyl farnesoate (MF) to increase during the embryogenesis. Endogenous MF were measured weekly over the embryogenesis of the crab, using HPLC with the aids of GC/MS and MS database (CAS 010485-70-8) for the identification of the hormone. Initial MF titers both in the hemolymph and embryos of intact control were at bottom levels and the hormone concentrations kept unchanged (p<0.05), reflecting physiological unnecessaries of the hormone in the embryogenesis. Eyestalk ablation significantly stimulated the crabs to increase endogenous MF in both tissues (p<0.0l). In the response of the embryos to the increased MF, no growth stimulations were observed, at least, in the first part of embryogenesis. The increased mortalities and immature sheddings of embryos resulted from the crabs under the influence of elevated MF in both tissues, instead, suggesting that the elevated MF against the crab's requirement blocked the normal developmental process of the crab embryos. These data can give crustacean endocrinologists some insights to understand the effects of the hormone on the crustacean reproduction studied previously in which JH analogs ambiguously affected the crustacean reproduction depending on the reproductive stages. The data also can give shrimp aquaculturists some implication of a possible generation of unfavorable shrimp seeds attributed to elevated egg MF originated from their eyestalk-ablated mother shrimp.

• Animal cells and systems
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• v.1 no.4
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• pp.657-663
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• 1997

The CD4 and CDS coreceptors, in conjunction with the T cell receptor (TCR) , make important contributions to the differentiation of thymocytes. They have been shown to be involved in the clonal deletion and positive selection processes during T cell development in thymus. To further analyze the role of CD4 and CDS proteins during T cell differentiation, we have generated transgenic mice constitutively expressing high levels of a native CD4 and a CD4{CDSa hybrid protein. The hybrid protein is composed of CD4 extracellular domain linked to the CD8a transmembrane region and cytoplasmic tail. The transgenes were driven by human beta-actin promoter, and therefore, they were expressed in all tissues examined including thymus, spleen, and lymph nodes. The resulting CD4 and CD4{CD8${\alpha}$transgenic mice were found to express the CD4 and CD4{CD8${\alpha}$ respectively, in developing thymocytes and peripheral T cells. The expression levels of transgenic proteins were 5-10 times higher than that of endogenous CD4 in thymus. However, total surface CD4 expression (CD4 or CD4{CD8${\alpha}$ transgenic protein plus endogenous CD4) of the transgenic mice were main. tained at similar levels compared to control littermates. Surface CD4 expression on CDS T cells, however, was significantly lower than that on cells expressing endogenous CD4. These results suggest that a total avidity between developing thymocytes and thymic stromal cells is impor. tant for differentiation of thymocytes.

• Environmental and Resource Economics Review
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• v.19 no.3
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• pp.459-483
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• 2010

This paper constructs the two-part tax-a combined form of output tax and entrance fee-for polluting oligopolists under endogenous entry. In the presence of external damage that varies exogenously with aggregate output, we show that the two-part tax produces the ex post Pigouvian rule and thus achieves the first-best optimum. We also examine a detailed analysis of the impact of the two-part tax on social welfare and government revenues. Finally, when estimation errors exist in the process of regulation, we identify the incentive conflicts between interest groups and analyze the effects of estimation errors on determining optimal tax. In particular, we show that if the regulator takes care of both welfare loss and revenue gain under the proposed two-part tax, not only over-estimation on the slope of external damage but also under-estimation on the slope of market demand should be taken into the policy consideration.

• Journal of Ginseng Research
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• v.22 no.1
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• pp.66-72
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• 1998

Studies were performed to determine the effect of Korean red ginseng (extract powder, spray-dried), it is made of choice 6-year-old raw ginseng roots, and processed by steaming and drying, on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of irradiated mice. Jejunal crypts were protected by pretreatment of red ginseng (1 mg/head, single I.P. at 24hours before irradiation, p<0.05). Red ginseng administration before irradiation (1 mg/head, single I.P at 24hours before irradiation) resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-Induced apoptosis in intestinal crypt cells was also reduced by treatment of red ginseng both pretreatment (P.O.: 2 mg/ml of drinking water for 7 days, p<0.005, I.P.: 1 mg/head, single I.P. at 24 hours before irradiation, p<0.005) and post-treatment (1 mg/head, single I.P at 30 minutes after irradiation, p<0.05). These results indicated that Korean red ginseng might be a useful radio-protector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of red ginseng and its fractions.

• Journal of Digital Convergence
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• v.11 no.9
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• pp.29-43
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• 2013

The dominant perspective on institutional change of the GRI is the environment-dependence. GRI's institutions are, however, prone to change due to the endogenous factors. Therefore, we need a dynamic alternative model to analyze the interaction between the exogenous and endogenous factors around the GRI's institutions. In this paper, authors examined the changes in GRI's funding system. The results were verified in the layering which is a one of the dynamic institutional change forms. Owing to the interaction between the exogenous and endogenous factors, institutional reform's layers of the institution funding expansion have been continuously accumulated in order to modify the Project-Based System(PBS). Eventually expansion layers of the institution funding have grown more quickly than the Project-Based System(PBS), as a result, GRI's funding system has been changing centered on the Block funding.

• Journal of the Korean association of regional geographers
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• v.22 no.2
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• pp.397-410
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• 2016

Although industrial complexes have played as an engine of the Korean economy for the last 40 years, the majority of industrial complexes shows limitations to the continuous growth such as a lack of innovation capabilities and social capital, conceived as a key to transforming into clusters of innovation. To overcome those problems, the Korean government embarked on the cluster policy from the mid 2000's, focusing on promoting the endogenous development capabilities of individual industrial complexes. Drawing upon the in-depth case study of the Gumi IT cluster, one of the representative large-scale industrial complexes in Korea, the authors conclude that the cluster policy has contributed to making the Gumi IT cluster enhance the capabilities of endogenous development through the facilitation of self-organizing learning communities within the cluster.