• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.125-133
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• 2007

Through open-sky policy, USA and European selected market principle of multiuser. However, in Asian case, major airlines monopolize airports. It is purpose that analyzes fare competition of Asian Hub Airport and the position of Incheon airport in Asia. Passengers required longer time and distance to go to the destination because direct flights decreases. But passengers increased in airport every year. Because of routes that decrease, airlines provide more services of flights. So airlines prefer to Hub Airports. As a result, both passengers and airlines are profitable by various routs and the increased frequency. On the assumption that distance and fare are related, the final formula is as following that defined the air fare from hub(H) to destination(Z) by logarithm. Analysis showed that log Rdist is not 1 but 0.08. As distance increases, fare doesn't increase. If distance from hub to destination airports is longer, Log dist_HZ is negative. It is that fare decreases from origin to destination via hub or that fare increases from hub to destination. HHI_HZ and HHI_AZ are negative. It means that if the degree of monopolization of hub and origin airports is lager, fare decreases from origin to destination via hub. Or fare increases from hub to destination. And it compares the Incheon airport with the other Asian hub airports and it examines the competitive fare by market division. As compared with the Incheon airport, Singapore, Beijing and Narita airports are higher fares. They compete with the other ones by Asian hub airports. But Hong Kong and Taipei airports must have more passengers through fare competition yet.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.215-231
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• 2020

Forest landscape models (FLMs) can be used to investigate the complex interactions of various ecological processes and patterns, which makes them useful tools to evaluate how environmental and anthropogenic variables can influence forest ecosystems. However, due to the large spatio-temporal scales in FLMs studies, parameterization and validation can be extremely challenging when applying to new study areas. To address this issue, we focused on the parameterization and application of a spatially explicit forest landscape model, LANDIS-II, to Mt. Gyebang, South Korea, with the use of the National Forest Inventory (NFI) and long-term ecological research (LTER) site data. In this study, we present the followings for the biomass succession extension of LANDIS-II: 1) species-specific and spatial parameters estimation for the biomass succession extension of LANDIS-II, 2) calibration, and 3) application and validation for Mt. Gyebang. For the biomass succession extension, we selected 14 tree species, and parameterized ecoregion map, initial community map, species growth characteristics. We produced ecoregion map using elevation, aspect, and topographic wetness index based on digital elevation model. Initial community map was produced based on NFI and sub-alpine survey data. Tree species growth parameters, such as aboveground net primary production and maximum aboveground biomass, were estimated from PnET-II model based on species physiological factors and environmental variables. Literature data were used to estimate species physiological factors, such as FolN, SLWmax, HalfSat, growing temperature, and shade tolerance. For calibration and validation purposes, we compared species-specific aboveground biomass of model outputs and NFI and sub-alpine survey data and calculated coefficient of determination (R²) and root mean square error (RMSE). The final model performed very well, with 0. 98 R² and 8. 9 RMSE. This study can serve as a foundation for the use of FLMs to other applications such as comparing alternative forest management scenarios and natural disturbance effects.

• Development and Reproduction
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• v.11 no.3
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• pp.187-193
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• 2007

Ethane 1,2-dimethane sulfonate(EDS), a Leydig cell specific toxicant, has been widely used to create the reversible testosterone withdrawal rat model. Though the maintenance of epididymal structure and function is highly dependent on the testosterone secreted from testis, its derivatives, dihydroxytestosterone(DHT) and estrogen, might have crucial roles. The aim of present study was to monitor the expression patterns of sex steroid receptors, cytochrome P450 aromatase(P450arom) and $5{\alpha}$-reductase in the rat epididymis up to 7 weeks after EDS injection. Adult male rats($350{\sim}400g$) were injected with a single does of EDS(75 mg/kg i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. The transcriptional activities of the target genes were evaluated by semi-quantitative RT-PCRs. The transcript level of estrogen receptor alpha($ER{\alpha}$) in EDS group was significantly higher than control level on week 1(P<0.01). After week 2, there was no significant difference in $ER{\alpha}$ levels between EDS group and control. The transcript level of estrogen receptor beta($ER{\beta}$) in EDS group was significantly higher than control level on week 1(P<0.05), lowered on weeks 2 and 3(P<0.05 and P<0.01, respectively), fluctuated during weeks 4 and 6, and elevated on week 7(P<0.05). The androgen receptor (AR) message levels increased significantly week 2(P<0.01), then returned to control level on week 3. In contrast, expression of cytochrome P450 aromatase(P450arom) decreased sharply during weeks $1{\sim}3$(P<0.01 on weeks 1 and 2; P<0.05 on week 3), then went back to control level on week 4. The mRNA level of $5{\alpha}$-reductase type 2($5{\alpha}$-RT2) increased significantly on week 4(P<0.01), then returned to control level. The present study indicated that EDS administration could induce reversible alterations in the transcriptional activities of sex steroid hormone receptors and androgenconverting enzymes in rat epididymis. EDS injection model will be useful to clarify the regulation mechanism of mammalian epididymal physiology.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.534-538
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• 2015

The purpose of this study was to investigate the biological benefits of apple peel. The antioxidant and anti-inflammatory activities of a 70% ethanol extract of apple peel were examined. The total phenolic compound and flavonoid contents of apple peel were $6.8{\pm}0.5mg$ gallic acid equivalent/g of fresh weight and $3.3{\pm}0.3mg$ catechin equivalent/g of fresh weight, respectively. Antioxidant activity was evaluated by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The DPPH radical scavenging activity of apple peel was $18.9{\pm}1.6$, $46.3{\pm}2.3$ and $58.1{\pm}3.9%$ at concentrations of 0.1, 0.5 and 1.0 mg/mL, respectively (p<0.05). The anti-inflammatory effect was investigated by measuring the inhibition of inflammatory enzymes. Apple peel significantly inhibited secretory phospholipase, cyclooxygenase-1, cyclooxygenase-2, and lipoxygenase activity by up to $53.5{\pm}2.3$, $13.4{\pm}1.8$, $64.8{\pm}5.4$ and $44.4{\pm}4.5%$, respectively (p<0.05). Taken together, these findings suggest that apple peel may act as an antioxidant by radical scavenging and may possess potential anti-inflammatory properties for suppressing the activity of inflammatory enzymes. These results also suggest that apple peel can be utilized as a health functional food ingredient possessing antioxidant and anti-inflammatory activities.

• Journal of Life Science
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• v.28 no.5
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• pp.605-614
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• 2018

Bee pollen has an outer wall which is resistant to both acidic and basic solutions and even the digestive enzymes in the gastrointestinal tract. Therefore, the oral bioavailability of bee pollen is only 10-15%. A previous study reported on wet-grinding technology which increased the extraction of active ingredients from bee pollen by 11 times. This study was designed to investigate the safety of wet-ground bee pollen. First, a single dose of wet-ground bee pollen was tested in both rats and beagle dogs at dosages of 5, 10, and 20 g/kg and 1.5, 3, and 6 g/kg, respectively. In rats, compound-colored stools were found in those administered 10 g/kg or more of wet-ground bee pollen. In beagle dogs, 6 g/kg of wet-ground bee pollen induced diarrhea in one male for four hours. However, no obvious clinical signs were found through the end of the experiment in rats and beagle dogs. In addition, no histological abnormality was found in all animals. The data indicates that a single dose of up to 20 g/kg of wet-ground bee pollen is safe. Next, the genetic toxicity of nano-sized bee pollen was tested. This study employed a bacterial reverse mutation test, a micronucleus assay, and a chromosomal aberration assay. In the micronucleus assay, there was no genetic toxicity up to the dosage of 2 g/kg. There was also no genetic toxicity in the bacterial reverse mutation test and chromosomal aberration assay. This data provides important information in developing nano-sized bee pollen into more advanced functional foods and herbal medicines.

• Journal of the Korean Geographical Society
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• v.29 no.4
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• pp.438-449
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• 1994

This paper focuses on recontextualizing geography curriculum, i.e. examining recent changing aspects in three geography curriculum locators-society, student and discipline of geography-and searching future directions of geography curriculum in light of such changes. For conciliation and reflection of changing aspects of each locators, this paper dealt with social issues and societal changes in terms of locator of society, increased concern to student and development of cognitive science in terms of students, and challenging views on science and the meaning of epistemological changes in geography in terms of discipline. As a result, three future directions in geography curriculum are searched : issue-based geography curriculum, thinking geography curriculum, geography curriculum toward equity and accessbility.

• Tuberculosis and Respiratory Diseases
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• v.55 no.5
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• pp.488-498
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• 2003

Background : Activation of the transcription factor NF-${\kappa}B$ has been shown to protect cells from tumor necrosis factor-alpha, chemotherapy, and radiation-induced apoptosis. NF-${\kappa}B$-dependent cIAP expression is a major antiapoptotic mechanism for that. NF-${\kappa}B$ activation and cIAP expression in A549 lung cancer cells which is relatively resistant to radiation-induced cell death were investigated for the mechanism of radioresistance. Materials and methods : We used A549 lung cancer cells and Clinac 1800C linear accelerator for radiation. Cell viability test was done by MTT assay. NF-${\kappa}B$ activation was tested by luciferase reporter gene assay, Western blot for $I{\kappa}B{\alpha}$ degradation, and electromobility shift assay. For blocking ${\kappa}B$, MG132 and transfection of $I{\kappa}B{\alpha}$-superrepressor plasmid construct were used. cIAP expression was analyzed by RT-PCR and cIAP2 promoter activity was performed using luciferase assay system. Results : MTT assay showed that cytotoxicity even 48 hr after radiation in A549 cells were less than 20%. Luciferas assay demonstrated weak NF-${\kappa}B$ activation of $1.6{\pm}0.2$ fold compared to PMA-induced $3.4{\pm}0.9$ fold. Radiation-induced $I{\kappa}B{\alpha}$ degradation was observed in Western blot and NF-${\kappa}B$ DNA binding was confirmed by EMSA. However, blocking NF-${\kappa}B$ using MG132 and $I{\kappa}B{\alpha}$-superrepressor transfection did not show any sensitizing effect for radiation-induced cell death. The result of RT-PCR for cIAP1 & 2 expression was negative induction while TNF-${\alpha}$ showed strong expression for cIAP1 & 2. The cIAP2 promoter activity also did not show any change compared to positive control with TNF-${\alpha}$. Conclusion : We conclude that activation of NF-${\kappa}B$ does not determine the intrinsic radiosensitivity of cancer cells, at least for the cell lines tested in this study.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.

• Journal of Haehwa Medicine
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• v.4 no.2
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• pp.255-272
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• 1996

소적백출산(消積白朮散)은 ${\ll}$화제국방(和劑局方)${\gg}$에 삼령백출산(蔘笭白朮散)에 정열해독약(淸熱解毒藥)인 와송(瓦松) 금은화(金銀花) 포공영(蒲公英)을 가미(加味)한 처방(處方)으로, 본방(本方)인 삼령백출산(蔘笭白朮散)은 비위허약(脾胃虛弱), 음식부진(飮食不振), 다곤소력(多困少力) 중만비대(中滿痺臺), 심정기천(心柾氣喘), 구토(嘔吐), 설사(泄瀉), 상한해수(傷寒咳嗽)를 치료목적(治療目的)으로 쓰여 온 이래(以來) 임상에서는 대편부실(大便不實), 구설(久泄), 옹달궤후(癰疸潰後) 불사식자(不思食者)를 치료(治療)하는데 다용(多用)되어 왔다. 종양(腫瘍)(Neoplasia)은 새로운 성장(成長)(New+ Glowth) 이라는 세포학적(細胞學的)으로 비정상세포(非正常細胞)의 과다증식(過多增殖)으로 인해 실질장기(實質臟器), 유강장기(有腔腸器), 및 골격(骨格), 피부조직(皮膚組織)에 비정상조직(非正常組織)을 형성(形成)하는 질환(疾患)이다. 현대적(現代的) 종양(腫瘍)과 유사(類似)한 한의학적(韓醫學的)인 병증(病症)은 ${\ll}$소문(素問)${\gg}$에서는 "궐산(厥疝), 복량(伏梁), 식적(息積)"으로 ${\ll}$영추(靈樞)${\gg}$에서는 "장담(腸覃), 석가"로 표시(表示)된 이후(以後)로 소원방(巢元方)은 징가, 식일, 석옹(石癰), 완저(緩疽), 석저(石疽) 등으로 표현(表現)하였다. 원인(原因)에 대(對)해서는 ${\ll}$내경(內經)${\gg}$에서는 허(虛)와 한기(寒氣), 한(寒) 열(熱)로 보았고, 그 외(外)의 학자(學者)들은 내허(內虛)와 기혈불순(氣血不順), 화(火), 한(寒), 기울(氣鬱), 음양불화(陰陽不和)등으로 보았다. 치료(治療)는 ${\ll}$내경(內經) 자법론(刺法論)${\gg}$에서 "정기재내(正氣在內) 사불가우(邪不可于)" 이라 하여 생명활동(生命活動)의 원동력(原動力)인 정기(正氣)의 역할(役割)을 강조(强調)하였고, ${\ll}$육원정기대론(六元正氣大論)${\gg}$에서는 "대적대취(大積大聚) 불가범야(不可犯也) 쇠기태반이지(衰其太半而止)"라 하여 공벌약(攻伐藥)을 과용(過用)하여 정기(正氣)를 손상(損傷)시켜서는 안된다고 하는 등 부정위주(扶正爲主), 거사위주(祛邪爲主) 혹은 부정거사(扶正祛邪) 겸용(兼用)의 방법(方法)이 혼용(混用)되고 있다. 현대(現代) 서양의학(西洋醫學)의 항암제(抗癌劑)는 치료효과(治療效果)는 우수(優秀)하지만 악심(惡心), 구토(嘔吐)를 비롯하여 골수억제효과(骨髓抑制效果)와 간(肝), 심(心), 신(腎), 폐(肺)의 손상(損傷)을 초래(招來)하는 등(等)의 부작용(副作用)을 나타내며, 빈번(頻繁)한 화학요법제(化學療法劑)의 투여(投與)로 인(因)한 암세포(癌細胞)의 약제저항성(藥劑抵抗性) 출현(出現)등이 항암제(抗癌劑)의 문제점(問題點)으로 제시(提示)되고 있다. 이에 저자(著者)는 비위기능(脾胃機能)을 강화(强化)시켜 정기형성(正氣形成)에 깊이 관여(關與)하는 삼령백출산(蔘笭白朮散)에 청열해독(淸熱解毒), 소종산결지제(消腫散結之劑)인 금은화(金銀花), 포공영(浦公英), 와송(瓦松)을 가미(加味)하여 암발생(癌發生) 백서(白鼠)에 투약(投藥)한 후(後) sarcoma 180암세포(癌細胞)에 대(對)한 생명연장효과(生命延長效果)와 항암제(劑)의 일종(一種)인 cis-platin을 이용(利用)하여 양방항암제(洋方抗癌劑)의 부작용(副作用)에 대(對)한 본(本) 방(方)의 효과(效果)를 실험(實驗)하여 관찰(觀察)하였던 바 다음과 같은 결론(結論)을 얻었다. 1. 소적백출산(消積白朮散)은 sarcoma 180 암세포(癌細胞) 이식종양(移植腫瘍)에 대(對)해 생명연장효과(生命延長效果)가 인정(認定)되었다. 2. 소적백출산(消積白朮散)은 치암제(治癌劑)인 cis-platin 치사독성(致死毒性)에 대(對)해 생존연장효과(生存延長效果)가 인정(認定)되었다. 3. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 생쥐 및 흰쥐에 있어서 유의성(有意性) 있는 체중감소억제효과(體重減少抑制效果) 및 serum BUN 상승억제효과(上昇抑制效果)가 인정(認定)되었다. 4. 소적백출산(消積白朮散)은 cis-platin 현독성(賢毒性) 흰쥐에 대(對)해 유의성(有意性) 있는 serum creatinine 상승억제효과(上昇抑制效果)가 나타났으며, cis-platin의 혈액학적(血液學的) 부작용(副作用)인 RBC, WBC 감소(減少)에 대(對)해 감소억제효과(減少抑制效果)가 인정(認定)되었다. 5. 소적백출산(消積白朮散)은 cis-platin 현독성(腎毒性) 흰쥐에 대(對)해 뇨량감소억제(尿量減少抑制) 효과(效果) 및 ureanitrogen과 creatinine 배수감소억제효과가 관찰(觀察)되었다. 이상(以上)의 결과(結果)로부터 소적백출산(消積白朮散)은 악성종양치료(惡性腫瘍治療) 및 항암제(劑)의 부작용(副作用)을 경감(輕減)시키는 데 응용(應用)할 수 있을 것으로 사료(思料)된다.

• Korean Journal of Environment and Ecology
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• v.23 no.5
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• pp.431-438
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• 2009

The main purpose of this research is to prepare and provide basic materials for the propagational strategy of eelgrass by investigating on the morphological adaptation of Korean Zostera marina to ocean currents. An eelgrass plant mainly consists of rhizome, leaf sheath, leaves and roots. The rhizome is the horizontal stem of the plant that serves as the backbone from which the leaves and roots emerge. The leaf sheath is the bundle at the base of the leaves that holds the leaves together, protecting the meristem, the primary growth point of the shoot. Leaves originate from a meristem which is protected by a sheath at the actively growing end of the rhizome. As the shoot grows, the rhizome elongates, moving across or within the sediment, forming roots as it progresses. The aggregated leaves from the leaf sheath are found to have two cell layers on one side and multiple layers of airy tissues called aerenchyma on the other. The aerenchyma tissues are developed in multi-layered cell structures surrounding the veins which are formed in the leaf sheath. Generative shoots are made of rhizomes, which are circular or ovoidal, stem, and spathe and spadix. The transverse section of rhizome and the stem and central floral axis is found to be circular, ovoid and in the shape of convex respectively, and the vascular bundle, which is a part of transport system, has one large tube in the center and two small tubes on both sides. The layers of collenchyma cells numbered from 12 to 15 in the stem, and from 7 to 12 in the rhizome. The seed coat is composed of sclereids, small bundles of sclerenchyma tissues, which prevent the influx of sea water from the outside and help endure the environmental stress. In conclusion, alternative multi-layer structure in circular, convex type aggregated leaf base are interpreted to morphological adaption as doing tolerable elastic structure through movement of seawater. The generative shoots develop long slim stem and branches in circular or ovoidal shapes to minimize the adverse impacts of sea current, which can be interpreted as the plant's morphological adaptation to its environment.