• Journal of Korean Society of Transportation
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• v.27 no.1
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• pp.143-155
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• 2009

A dynamic traffic assignment (DTA) has recently been implemented in many practical projects. The core of dynamic model is the inclusion of time scale. If excluding the time dimension from a DTA model, the framework of a DTA model is similar to that of static model. Similar to static model, with given exogenous travel demand, a DTA model loads vehicles on the network and finds an optimal solution satisfying a pre-defined route choice rule. In most DTA models, the departure pattern of given travel demand is predefined and assumed as a fixed pattern, although the departure pattern of driver is changeable depending on a network traffic condition. Especially, for morning peak commute where most drivers have their preferred arrival time, the departure time, therefore, should be modeled as an endogenous variable. In this paper, the authors point out some shortcomings of current DTA model and propose an alternative approach which could overcome the shortcomings of current DTA model. The authors substitute a traditional definition for time-dependent OD table by a new definition in which the time-dependent OD table is defined as arrival time-based one. In addition, the authors develop a new DTA model which is capable of finding an equilibrium departure pattern without the use of schedule delay functions. Three types of objective function for a new DTA framework are proposed, and the solution algorithms for the three objective functions are also explained.

• Journal of Applied Biological Chemistry
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• v.58 no.3
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• pp.273-279
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• 2015

Phaeodactylum tricornutum is a model diatom that its genomic information and biological tools are well established. In this study, a gene encoding (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase (PtHDR), a terminal enzyme of the methylerythritol phosphate pathway regulating chlorophyll and carotenoid biosynthesis, was isolated from P. tricornutum. The isolated gene was cloned into pPha-T1 vector containing fcpA promoter to prepare pPha-T1-HDR plasmid. As a positive control, pPha-T1-eGFP plasmid was constructed with egfp gene. Stable nuclear transformation was carried out with these plasmids by particle bombardment method and zeocin resistant colonies of P. tricornutum were selected on f/2 agar plate. In result, transformation efficiency was evaluated according to the amount of plasmid DNA coated with gold particles. Integration of introduced plasmids was confirmed with genomic DNA of each transformant by polymerase chain reaction. The eGFP fluorescence was visible in the cytoplasm, indicating that eGFP was successively expressed in P. tricornutum system. The transcript level of exogenous Pthdr gene was evaluated with the obtained transformants. The results presented here demonstrated that introduction of Pthdr gene into P. tricornutum chromosome succeeded and expression of PtHDR was enhanced under the fcpA promoter.

• Archives of Pharmacal Research
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• v.24 no.2
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• pp.136-143
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• 2001

Fumonisins are specific inhibitors of ceramide synthase in sphingolipid metabolism. An alteration in sphingolipid metabolism as a result of fumonisin exposure is related to cell death (Yoo et al., 1992). The objective of this study was to investigate whether elevated free sphinganine levels are related to the sensitivity of cultured cells to fumonisin exposure. Fumonisin $B_1$ elevated the intracellular free sphinganine concentraions in both LLC-$PK_1$ and Chinese hamster ovary (CHO) cells. However, CHO cells are resistant to fumonisin cytotoxicity at 50${u}m$, while LLC-$PK_1$ cells are sensitive at concentrations greater than 357M. The intracellular concentration of free sphinganine in LLC-$PK_1$ cells treated at 50${u}m$ fumonisin $B_1$ for 72 h was approximately 1450 pmol/mg protein relative to the 37 pmol observed in the control culture. Under the same conditions, the population of apoptotic cells in the 50${u}m$ fumonisin $B_1$-treated culture was approximately 37% of the total compared to 12% in the control. The caspase III-like activity after 72 h in the 50${\mu}$M fumonisin $B_1$-exposed culture Increased to approximately 50 $pmol/mg$ protein/hr compared to 6 $pmol/mg$ protein/hr in the control. L-cycloserine, a serine palmitoyltransferase inhibitory reduced the fumonisin $B_1$-stimulated caspase III-like activity down to the control level. Under the same culture conditions, the intracellular concentration of free sphinganine after-cycloserine plus fumonisin $B_1$ treatment was 140 pmol/mg protein compared to 1450 $pmol/mg$ protein in fumonisin $B_1$ alone. The intracellular concentration of free sphinganine in CHO cells treated with 50${u}m$ fumonisin $B_1$ for 72 h was al)proximately 460 pmol/mg protein, indicating that the mass amount of elevated free sphinganine in the CHO cells was about 32% of that in LLC-$PK_1$ cells. Adding exogenous sphinganine to the CHO cells along with 50${u}m$ fumonisin $B_1$ treatment for 72 h caused both necrosis and apoptosis. In conclusion, the elevated endogenous sphinganine acts as a contributing factor to the fumonisin-induced cell death.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.87-96
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• 1994

Background : Since tumor necrosis factor was discovered in 1975, TNF has been well known about its cytotoxic effect on tumor cells in vivo and in vitro. According to the recent improvement of molecular biological techinques, it is possible that exogenous TNF gene is transferred to tumor cells and is expressed in theirs. By virtue of TNF gene transfer, we have expected that TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells in vivo without systemic side effect. The expected mechanisms in which antitumor effects of TNF expressed in TNF-gene-transferred tumor cells are working would be as followings. In the first mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill tumor cells around(like homicide). In the second mechanism, TNF expressed in TNF-gene-transferred tumor cells would kill themselves(like suicide). In the third mechanism, TNF expressed in TNF-gene-transferred tumor cells would recruit immune effector cells and kill tumor cells indirectly. In the last mechanism, TNF expressed in TNF-gene-transferred tumor cells would augment cytokine such as interferon-$\gamma$ to kill tumor cells. Among these four mechanisms of antitumor effect, only the second mechanism has not been established yet. Therefore, to elucidate the second mechanism, We performed this study. Method : We transferred TNF-$\alpha$ gene to NCI-H2058, a human mesothelioma cell line and WEHI164, a murine fibrosarcoma cell line by using retroviral vector(pLT12SNTNF). And, We determined by using MTT assay whether TNF expressed in TNF-gene-transferred tumor cell lines would kill themselves like suicide or not. Then, if TNF-gene-transferred tumor cell lines would not suicide themselves, I would know more about the TNF sensitivity of TNF-gene-transferred tumor cell lines to exogenous TNF also by MTT assay. Result : NCI-H2058 and WEHI164 which were sensitive to TNF, became far less sensitive to endogenous and exogenous TNF after being transferred TNF-$\alpha$ gene to. Conclusion : TNF-gene-transfer to NCI-H2058 and WEHI164 gave them resistance to TNF.

• Development and Reproduction
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• v.11 no.2
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• pp.111-119
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• 2007

Differentiation of cells can be induced through modulation of endogenous regulators using exogenous factors. Useful transfection systems to transport a specific exogenous regulator into cell have been tried but still there are many obstacles to overcome. In this study, we examined the transfection efficiency of cell permeable peptides (CPPs) in mouse embryonic stem cell under the various conditions. To identify the CPP-mediated translocation of a protein, we employed recombinant CPP-enhanced green fluorescent protein (EGFP). Viability of R1 cells was different between experimental groups depending on the kind of CPP and the concentration of CPP-EGFP. Translocation of CPP-EGFPs into the R1 cells was not detected until 30 min after CPP-EGFPs treatment in all groups. After 1 hr, translocation of pEP-1-EGFP-N was detected, but it could not be detected in the other group. Transfection of pEP-1EGFP-N was independent on its concentration. The time course did not show saturation even after 24 hr in pEP-1-EGFP-N. These results showed that the permeability depended on the kind of CPP and the location of His-tag in the case of examined CPPs, and did not need biological energy. On summary, the efficiency of transfection of CPP-EGFP depends on the CPP sequences but the culture time is not a key factor in transfection for the mouse embryonic stem cell. For the future studies to improve the efficiency of translocation of protein into embryonic stem cells, it is needed to develop modified CPP or mediator. The studies would be very useful to induce the differentiation of embryonic stem cells.

• Journal of Life Science
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• v.24 no.1
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• pp.86-91
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• 2014

Trichoplusia ni cells are used as a host permissive cell line in the baculovirus expression system, which is useful for large-scale production of human sugar transport proteins. However, the activity of endogenous sugar transport systems in insect cells is extremely high. Therefore, the transport activity resulting from the expression of exogenous transporters is difficult to detect. Furthermore, very little is known about the nature of endogenous insect transporters. To exploit the expression system further, the effect of D-fructose on 2-deoxy-D-glucose (2dGlc) transport by T. ni cells was investigated, and T. ni cell-expressed human transporters were photolabeled with [$^3H$] cytochalasin B to develop a convenient method for measuring the biological activity of insect cell-expressed transporters. The uptake of 1 mM 2dGlc by uninfected- and recombinant AcMPV-GTL infected cells was examined in the presence and absence of 300 mM of D-fructose, with and without $20{\mu}M$ of cytochalasin B. The sugar uptake in the uninfected cells was strongly inhibited by fructose but only poorly inhibited by cytochalasin B. Interestingly, the AcMPV-GTL-infected cells showed an essentially identical pattern of transport inhibition, and the rate of 2dGlc uptake was somewhat less than that seen in the non-infected cells. In addition, a sharply labeled peak was produced only in the AcMPV-GTL-infected membranes labeled with [$^3H$] cytochalasin B in the presence of L-glucose. No peak of labeling was seen in the membranes prepared from the uninfected cells. Furthermore, photolabeling of the expressed protein was completely inhibited by the presence of D-glucose, demonstrating the stereoselectivity of labeling.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.139-143
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• 2010

Quail is a very useful animal model for studying vertebrate development because of its small body size and unique reproductive traits. This species is also ideal model for producing germline chimeras via transferring exogenous primordial germ cells (PGCs) into the recipient embryo. To increase the contribution efficiency of donor PGCs into recipients' tissues, decreasing the population of endogenous PGCs has been rate-limiting factor. We therefore conducted this study to investigate if gamma ($\gamma$)-irradiation depletes endogenous PGCs in developing quail embryo. Firstly, freshly laid stage X quail embryos were irradiated with various output of $\gamma$-irradiation and its teratogenic effect on the embryo was evaluated. Although a dose-dependent increase in the number of embryo showing malformation was found as the output increased (0, 250, 500, 750, and 1,000 rads), only a maximum of 10.1% of embryos were abnormal in 1,000 rads. Immunocytochemical analysis using the QCR1 antibody, which is specific marker for quail PGCs, was conducted to analyze the effect of sterilization. As results, $\gamma$-rays at a dose-rate of 500 rads/73 sec onto undeveloped stage X embryo significantly reduced the number of germ cells to an average of 75.55 % and 82.03 % in male and female embryos, respectively. We conclude that $\gamma$-ray selectively targets PGCs while affects minimally to the somatic development in quail embryo. Our results will not only provide important data for germline chimera production but can be used for analyzing the effect of ionized rays on the differentiating germ cells in various stages during animal development.

• Journal of muscle and joint health
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• v.8 no.1
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• pp.122-140
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• 2001

The aims of this study were to understand and to predict the determinent factors affecting the exercise behaviors and physical fitness by testing the Pender's revised health promotion model, and to help the patients with rheumatoid arthritis and osteoarthritis perform the continous exercise program, and to help them maximize the physical effect such as muscle strength, endurance, and functional status and mental effects including self efficacy and quality of life, and improve the physical and mental well being, and to provide a basis for the nursing intervention strategies. Of the selected variables in this study, the endogenous variables included the physical fitness, exercise score, exercise participation, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue) and the exogenous variables included personal sociocultural factor(education level), personal biologic factor(body mass index), personal psychologic factor(perceived health status) and prior related behavior factors(previous participation in exercise, life-style). We analyzed the clinical records of 208 patients with rheumatoid arthritis and degenerative arthritis who visited the outpatient clinics at H university hospital in Seoul. Data were composed of self reported qustionnaire and good of fitness score which were obtained by padalling the ergometer of bicycle for 9 minutes. SPSS Win 8.0 and Window LISREL 8.12a were used for statistical analysis. Of 75 hypothetical paths that influence on physical fitness, exercise participation, exercise score, perceived benefits of action, perceived barriers of action to exercise, activity-related affect(depression) and perceived self-efficacy, interpersonal influences(family support), situational factors(duration of arthritis, fatigue), 40 were supported. The physical fitness was directly influenced by life-style, perceived health status, education level, family support, fatigue, which explained 12% of physical fitness. The exercise participation were directly influenced by life-style, education level, past exercise behavior, perceived benefits of action, perceived barriers of action, depression and duration of arthritis, which explained 47% of exercise participation. Exercise score were directly affected by perceived self efficacy. BMI, life-style, past exercise behavior, perceived benefits of action, family support, perceived health status. perceived barriers of action, and fatigue, which explained 70%. Perceived benefits of action was directly influenced by BMI, life-style, which explained 39%. Perceived barriers of action were directly influeced by past exercise behavior, perceived health status, which explained 7%. Perceived self efficacy were directly influeced by level of education, perceived health status, life-style, which explained 57%. Depression were directly influeced by past exercise behavior, BMI, life-style, which explained 27%. Family support were directly influeced by life-style, perceived health status, which explained 29%. Fatigue were directly influeced by BMI, life-style, perceived health status. which explained 41%. Duration of arthritis were directly influeced by life-style, past exercise behavior, BMI, which explained 6%. In conclusion, important variables for physical fitness were life-style, and variable affecting exercise participation were life-style. Perceived self-efficacy of exercise was a significant predictor of exercise score. BMI, Life-style, perceived benefits of action, family support, past exercise behavior showed direct effects on perceived self-efficacy. Therefore, disease related factor should be minimized for physical performance and well being in nursing intervention for patients with rheumatoid arthritis, and plans to promote and continue exercise should be seeked to reduce disability. In addition, Exercise program should be planned and performed by the exact evaluation of exercise according to the ability of the patients and the contents to improve the importance of exercise and self efficacy in self control program, dedicated educational program should be involved. This study suggest that the methods to reduce the disease related factors, the importance of daily life-style, recognition of benefit of exercise, and educational program to promote self efficacy should be considered in the exercise behavior promotion and nursing intervention for continous performance. The significance of this study is also thought to provide patients with chronic arthritis the specific data for maximal physical and mental well being through exercise, chronic therapeutic procedure, daily adaptation and confrontation in nursing intervention.

• Journal of Global Scholars of Marketing Science
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• v.19 no.4
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• pp.57-63
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• 2009

With an exponential increase in electronic commerce (e-commerce), marketers are attempting to gain a competitive advantage by emphasizing service quality and post interaction service aspects, which leads to customer satisfaction or behavioral consequence. Particularly for apparel, service quality is one of the key determinants in encouraging customer e-loyalty, and hence the success of apparel retailing in the context of electronic commerce. Therefore, this study explores e-service quality (E-SERVQUAL) factors and their unique effects on e-loyalty for apparel online shopping based on Parasuraman et al' s (2005) framework. Specific objectives of this study are to identify underlying dimension of E-SERVQUAL, and analyze a structural model for examining the effect of E-SERVQUAL on e-loyalty for online apparel shopping. For the theoretical framework of service quality in the context of online shopping, literatures on traditional and electronic service quality factors were comparatively reviewed, and two aspects of core and recovery services were identified. This study hypothesized that E-SERVQUAL has an effect on e-loyalty; customer satisfaction has a positive effect on e-service loyalty for apparel online shopping; and customer satisfaction mediates in the effect of E-SERVQUAL on e-loyalty for apparel online shopping. A self-administered questionnaire was developed based on literatures. A total of 252 usable questionnaires were obtained from online consumers who had purchase experience with online shopping for apparel products and reside in standard metropolitan areas, in the United States. Factor analysis (e.g., exploratory, confirmatory) was conducted to assess the validity and reliability and the structural equation model including measurement and structural models was estimated via LISREL 8.8 program. Findings showed that the E-SERVQUAL of shopping websites for apparel consisted of five factors: Compensation, Fulfillment, Efficiency, System Availability, and Responsiveness. This supports Parasuraman (2005)'s E-S-QUAL encompassing two aspects of core service (e.g., fulfillment, efficiency, system availability) and recovery related service (e.g., compensation, responsiveness) in the context of apparel shopping online. In the structural equation model, there are five exogenous latent variables for e-SERVQUAL factors; and two endogenous latent variables (e.g., customer satisfaction, e-loyalty). For the measurement model, the factor loadings for each respective construct were statistically significant and were greater than .60 and internal consistency reliabilities ranged from .85 to .88. In the estimated structural model of the e-SERVEQUAL factors, the system availability was found to have direct and positive effect on e-loyalty, whereas efficiency had a negative effect on e-loyalty for apparel online shopping. However, fulfillment was not a significant predictor for explaining consequences of E-SERVQUAL for apparel online shopping. This finding implies that perceived service quality of system available was likely to increase customer satisfaction for apparel online shopping. However, it was not supported that e-loyalty was determined by service quality, because service quality has an indirect effect on e-loyalty (i.e., repurchase intention) by mediating effect of value or satisfaction in the context of online shopping for apparel. In addition, both compensation and responsiveness were found to have a significant impact on customer satisfaction, which influenced e-loyalty for apparel online shopping. Thus, there was significant indirect effect of compensation and responsiveness on e-loyalty. This suggests that the recovery-specific service factors play an important role in maximizing customer satisfaction levels and then maintaining customer loyalty to the online shopping site for apparel. The findings have both managerial and research implications. Fashion marketers can establish long-term relationship with their customers based on continuously measuring customer perceptions for recovery-related service quality, such as quick responses to problem and returns, and compensation for customers' problem after their purchases. In order to maintain e-loyalty, recovery services play an important role in the first choice websites for consumers to purchase clothing. Given that online consumers may shop anywhere, a marketing strategy for improving competitive advantages is to provide better service quality, maximize satisfaction, and turn to creating customers' e-loyalty for apparel online shopping. From a researcher's perspective, there are some limitations of this research that should be considered when interpreting its findings. For future research, findings provide a basis for the further study of this important topic along both theoretical and empirical dimensions. Based on the findings, more comprehensive models for predicting E-SERVQUAL's consequences can be developed and tested. For global fashion marketing, this study can expand to a cross-cultural approach into e-service quality for apparel by including multinational samples.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.471-480
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• 1985

Recently several synthetic chemicals inhibiting biosynthesis of gibberellic acids were found to be effective in preventing cereal crops from lodging by reducing culm length. The present study aimed to clarify the extent of practical manipulation of the culm length of the rice crop by changing the endogenous level of gibberellic acids with exogenous application of GA$_3$ or GA biosynthesis inhibitor. Three rice cultivars, 'Jinheung', 'Minehikari' (Japonica) and 'Hangangchal' (semi-dwarf Indica x Japonica) were treated with GA$_3$ (0, 20, 50 and 100 ppm solution) and an anti-gibberellin, paclobutrazol (0, 100, 200 and 300 g ai/ha) at three growth stages (maximum tillering, panicle initiation and meiotic stage), respectively. The application of GA$_3$ (50, 100 ppm) at maximum tillering stage and panicle initiation stage promoted the elongation of the 5th internodes from the top and GA$_3$ applied at meiotic stage promoted remarkably the elongation of the 3rd internodes. Culm was most elongated when GA$_3$ was applied at maximum tillering stage in 'Jinheung', at panicle initiation stage in 'Minehikari' and at meiotic stage in 'Hangangchal'. Paclobutrazol shortened the 4th and 5th internodes from the top when it was applied at maximum tillering stage and panicle initiation stage and the 2nd and 3rd internodes when it was applied at meiotic stage in the three cultivars. The semi-dwarf Indica x Japonica variety responded to a greater extent to the GA$_3$ and to a less extent to the anti-gib berellin than the Japonica varieties. The effect of GA$_3$ and paclobutrazol on the panicle length and the number of spikelets per panicle varied with time and dose of their application as well as with variety.