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A Study on Space Creation and Management Plan according to Characteristics by Type in Each Small-Scale Biotope in Seoul - Base on the Amphibian Habitats - (서울시 소규모 생물서식공간 유형별 특성에 따른 조성 및 관리방안 연구 - 양서류 서식지를 중심으로 -)

  • Park, Ha-Ju;Han, Bong-Ho;Kim, Jong-Yup
    • Journal of the Korean Institute of Landscape Architecture
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    • v.52 no.2
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    • pp.110-126
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    • 2024
  • This study conducted a classification of small-scale biological habitats created in Seoul to analyze and synthesize location characteristics, habitat structure, biological habitat functions, and threat factors of representative sites, as well as derive creation and management problems according to the ecological characteristics. The aim was to suggest improvement measures and management items. Data collected through a field survey was used to categorize 39 locations, and 8 representative sites were selected by dividing them into location, water system, and size as classification criteria for typification. Due to the characteristics of each type, the site was created in an area where amphibian movement was disadvantageous due to low or disconnected connectivity with the hinterland forest, and the water supply was unstable in securing a constant flow and maintaining a constant water depth. The habitat structure has a small area, an artificial habitat structure that is unfavorable for amphibians, having the possibility of sediment inflow, and damage to the revetment area. The biological habitat function is a lack of wetland plants and the distribution of naturalized grasses, and threats include the establishment of hiking trails and decks in the surrounding area. Artificial disturbances occur adjacent to facilities. When creating habitats according to the characteristics of each type, it was necessary to review the possibility of an artificial water supply and introduce a water system with a continuous flow in order to connect the hinterland forest for amphibian movement and locate it in a place where water supply is possible. The habitat structure should be as large as possible, or several small-scale habitats should be connected to create a natural waterfront structure. In addition, additional wetland plants should be introduced to provide shelter for amphibians, and facilities such as walking paths should be installed in areas other than migration routes to prevent artificial disturbances. After construction, the management plan is to maintain various water depths for amphibians to inhabit and spawn, stabilize slopes due to sediment inflow, repair damage to revetments, and remove organic matter deposits to secure natural grasses and open water. Artificial management should be minimized. This study proposed improvement measures to improve the function of biological habitats through the analysis of problems with previously applied techniques, and based on this, in the future, small-scale biological habitat spaces suitable for the urban environment can be created for local governments that want to create small-scale biological habitat spaces, including Seoul City. It is significant in that it can provide management plans.

무령왕릉보존에 있어서의 지질공학적 고찰

  • 서만철;최석원;구민호
    • Proceedings of the KSEEG Conference
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    • 2001.05b
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    • pp.42-63
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    • 2001
  • The detail survey on the Songsanri tomb site including the Muryong royal tomb was carried out during the period from May 1 , 1996 to April 30, 1997. A quantitative analysis was tried to find changes of tomb itself since the excavation. Main subjects of the survey are to find out the cause of infiltration of rain water and groundwater into the tomb and the tomb site, monitoring of the movement of tomb structure and safety, removal method of the algae inside the tomb, and air controlling system to solve high humidity condition and dew inside the tomb. For these purposes, detail survery inside and outside the tombs using a electronic distance meter and small airplane, monitoring of temperature and humidity, geophysical exploration including electrical resistivity, geomagnetic, gravity and georadar methods, drilling, measurement of physical and chemical properties of drill core and measurement of groundwater permeability were conducted. We found that the center of the subsurface tomb and the center of soil mound on ground are different 4.5 meter and 5 meter for the 5th tomb and 7th tomb, respectively. The fact has caused unequal stress on the tomb structure. In the 7th tomb (the Muryong royal tomb), 435 bricks were broken out of 6025 bricks in 1972, but 1072 bricks are broken in 1996. The break rate has been increased about 250% for just 24 years. The break rate increased about 290% in the 6th tomb. The situation in 1996 is the result for just 24 years while the situation in 1972 was the result for about 1450 years. Status of breaking of bircks represents that a severe problem is undergoing. The eastern wall of the Muryong royal tomb is moving toward inside the tomb with the rate of 2.95 mm/myr in rainy season and 1.52 mm/myr in dry season. The frontal wall shows biggest movement in the 7th tomb having a rate of 2.05 mm/myr toward the passage way. The 6th tomb shows biggest movement among the three tombs having the rate of 7.44mm/myr and 3.61mm/myr toward east for the high break rate of bricks in the 6th tomb. Georadar section of the shallow soil layer represents several faults in the top soil layer of the 5th tomb and 7th tomb. Raninwater flew through faults tnto the tomb and nearby ground and high water content in nearby ground resulted in low resistance and high humidity inside tombs. High humidity inside tomb made a good condition for algae living with high temperature and moderate light source. The 6th tomb is most severe situation and the 7th tomb is the second in terms of algae living. Artificial change of the tomb environment since the excavation, infiltration of rain water and groundwater into the tombsite and bad drainage system had resulted in dangerous status for the tomb structure. Main cause for many problems including breaking of bricks, movement of tomb walls and algae living is infiltration of rainwater and groundwater into the tomb site. Therefore, protection of the tomb site from high water content should be carried out at first. Waterproofing method includes a cover system over the tomvsith using geotextile, clay layer and geomembrane and a deep trench which is 2 meter down to the base of the 5th tomb at the north of the tomv site. Decrease and balancing of soil weight above the tomb are also needed for the sfety of tomb structures. For the algae living inside tombs, we recommend to spray K101 which developed in this study on the surface of wall and then, exposure to ultraviolet light sources for 24 hours. Air controlling system should be changed to a constant temperature and humidity system for the 6th tomb and the 7th tomb. It seems to much better to place the system at frontal room and to ciculate cold air inside tombs to solve dew problem. Above mentioned preservation methods are suggested to give least changes to tomb site and to solve the most fundmental problems. Repairing should be planned in order and some special cares are needed for the safety of tombs in reparing work. Finally, a monitoring system measuring tilting of tomb walls, water content, groundwater level, temperature and humidity is required to monitor and to evaluate the repairing work.

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Usefulness of Stomach Extension after Drinking Orange Juice in PET/CT Whole Body Scan (PET/CT 전신 영상에서 오렌지 주스(Orange Juice)를 이용한 위장 확장 영상의 유용성)

  • Cho, Seok-Won;Chung, Seok;Oh, Shin-Hyun;Park, Hoon-Hee;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.13 no.1
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    • pp.86-92
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    • 2009
  • Purpose: The PET/CT has a clear distinction on the lesion of the functional image by adding anatomical information. It also could reduce the examination time using CT data as the attenuation-correction. When the stomach was contracted from a fast, it could bring a misinterpretation of the cancer of the lesion with a presence of physiological $^{18}F$-FDG uptake in stomach and it occasionally would bring an additional scan to confirm. To complement this shortcoming, the method that the patients had water before the examination to extend the stomach had been attempted. However, a short excretion time of the stomach did not give sufficiently extended image of the stomach. Then the patients had additional water and had the examination again. Therefore, the noticed fact is that the stomach excretion time depends on calories, protein content, and the level of carbohydrate. In this study, we use an orange juice to evaluate the extension of the stomach and usefulness of it. Materials and Methods: PET/CT scan were obtained on total 150 of patient from February 2008 to October2008, There were 3 groups in this study and each group had 50 patients. First group drank nothing, Second group drank water and third group drank orange juice. The patients (man 25, female 25) not drinking are the age of 30~71 years old (average: 54), the patients (man: 25, female: 25) drinking water (400 cc) are the age of 28~71 years old (average: 54) and the patients (man: 25, female: 25) drinking orange juice (400 cc) are the age of 32~74 years old (average: 56). The patients were fasted in 6-8 hours before the test, the patients were not diabetic. $^{18}F$-FDG 370~555 MBq were injected intravenously. The patients were in stable position for 1 hour, than the image was obtained. The patients drank water and other patients drank orange juice before Whole body scan. The image scan started from mid-femur to skull base. The emission scan acquired for three minutes per bed and the images were reconstructed. Stomach extension analysis is measured from vertical and horizontal length. Results: Stomach Extension was described as the vertical length of the Non Drink Group was $1.20{\pm}0.50\;cm$, horizontal length was $1.4{\pm}0.53\;cm$, the vertical length of the Water Drink Group was $1.67{\pm}0.63\;cm$, horizontal length was $1.65{\pm}0.77\;cm$, the vertical length of Orange juice Drink Group was $3.48{\pm}0.77\;cm$, horizontal length was $3.66{\pm}0.77\;cm$ in coronal image. Stomach Extension was described the vertical length of the Non Drink Group was $2.03{\pm}0.62\;cm$, horizontal length was $1.69{\pm}0.68\;cm$, the vertical length of Water Drink Group was $5.34{\pm}1.62\;cm$, horizontal length was $2.45{\pm}0.72\;cm$, the vertical length of Orange juice Drink Group was $7.74{\pm}1.62\;cm$, horizontal length was $3.57{\pm}0.77\;cm$ in transverse image. The Stomach Extension has specific differences (p<0.001). The SUVs shows the Non Drink Group were measured as Liver $2.52{\pm}0.42$, Lung $0.51{\pm}0.14$, the Water Drink Group were measured as Liver $2.47{\pm}0.38$, Lung $0.50{\pm}0.14$, Orange juice Drink Group were measured as Liver $2.47{\pm}0.38$, Lung $0.50{\pm}0.14$. The SUVs did not have specific differences (p>0.759). Conclusions: There was not a large difference of SUV in three groups. When the patients drank Orange juice and water, the range extension of stomach was higher than without drinking nothing and it was possible to acquire fully extended images. Therefore, it will be possible that unnecessary additional stomach scans will be reduced by drinking orange juice before the examination so that the patients' claim from uncomfortable and long period of fast will be minimized.

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Analysis of Greenhouse Thermal Environment by Model Simulation (시뮬레이션 모형에 의한 온실의 열환경 분석)

  • 서원명;윤용철
    • Journal of Bio-Environment Control
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    • v.5 no.2
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    • pp.215-235
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    • 1996
  • The thermal analysis by mathematical model simulation makes it possible to reasonably predict heating and/or cooling requirements of certain greenhouses located under various geographical and climatic environment. It is another advantages of model simulation technique to be able to make it possible to select appropriate heating system, to set up energy utilization strategy, to schedule seasonal crop pattern, as well as to determine new greenhouse ranges. In this study, the control pattern for greenhouse microclimate is categorized as cooling and heating. Dynamic model was adopted to simulate heating requirements and/or energy conservation effectiveness such as energy saving by night-time thermal curtain, estimation of Heating Degree-Hours(HDH), long time prediction of greenhouse thermal behavior, etc. On the other hand, the cooling effects of ventilation, shading, and pad ||||&|||| fan system were partly analyzed by static model. By the experimental work with small size model greenhouse of 1.2m$\times$2.4m, it was found that cooling the greenhouse by spraying cold water directly on greenhouse cover surface or by recirculating cold water through heat exchangers would be effective in greenhouse summer cooling. The mathematical model developed for greenhouse model simulation is highly applicable because it can reflects various climatic factors like temperature, humidity, beam and diffuse solar radiation, wind velocity, etc. This model was closely verified by various weather data obtained through long period greenhouse experiment. Most of the materials relating with greenhouse heating or cooling components were obtained from model greenhouse simulated mathematically by using typical year(1987) data of Jinju Gyeongnam. But some of the materials relating with greenhouse cooling was obtained by performing model experiments which include analyzing cooling effect of water sprayed directly on greenhouse roof surface. The results are summarized as follows : 1. The heating requirements of model greenhouse were highly related with the minimum temperature set for given greenhouse. The setting temperature at night-time is much more influential on heating energy requirement than that at day-time. Therefore It is highly recommended that night- time setting temperature should be carefully determined and controlled. 2. The HDH data obtained by conventional method were estimated on the basis of considerably long term average weather temperature together with the standard base temperature(usually 18.3$^{\circ}C$). This kind of data can merely be used as a relative comparison criteria about heating load, but is not applicable in the calculation of greenhouse heating requirements because of the limited consideration of climatic factors and inappropriate base temperature. By comparing the HDM data with the results of simulation, it is found that the heating system design by HDH data will probably overshoot the actual heating requirement. 3. The energy saving effect of night-time thermal curtain as well as estimated heating requirement is found to be sensitively related with weather condition: Thermal curtain adopted for simulation showed high effectiveness in energy saving which amounts to more than 50% of annual heating requirement. 4. The ventilation performances doting warm seasons are mainly influenced by air exchange rate even though there are some variations depending on greenhouse structural difference, weather and cropping conditions. For air exchanges above 1 volume per minute, the reduction rate of temperature rise on both types of considered greenhouse becomes modest with the additional increase of ventilation capacity. Therefore the desirable ventilation capacity is assumed to be 1 air change per minute, which is the recommended ventilation rate in common greenhouse. 5. In glass covered greenhouse with full production, under clear weather of 50% RH, and continuous 1 air change per minute, the temperature drop in 50% shaded greenhouse and pad & fan systemed greenhouse is 2.6$^{\circ}C$ and.6.1$^{\circ}C$ respectively. The temperature in control greenhouse under continuous air change at this time was 36.6$^{\circ}C$ which was 5.3$^{\circ}C$ above ambient temperature. As a result the greenhouse temperature can be maintained 3$^{\circ}C$ below ambient temperature. But when RH is 80%, it was impossible to drop greenhouse temperature below ambient temperature because possible temperature reduction by pad ||||&|||| fan system at this time is not more than 2.4$^{\circ}C$. 6. During 3 months of hot summer season if the greenhouse is assumed to be cooled only when greenhouse temperature rise above 27$^{\circ}C$, the relationship between RH of ambient air and greenhouse temperature drop($\Delta$T) was formulated as follows : $\Delta$T= -0.077RH+7.7 7. Time dependent cooling effects performed by operation of each or combination of ventilation, 50% shading, pad & fan of 80% efficiency, were continuously predicted for one typical summer day long. When the greenhouse was cooled only by 1 air change per minute, greenhouse air temperature was 5$^{\circ}C$ above outdoor temperature. Either method alone can not drop greenhouse air temperature below outdoor temperature even under the fully cropped situations. But when both systems were operated together, greenhouse air temperature can be controlled to about 2.0-2.3$^{\circ}C$ below ambient temperature. 8. When the cool water of 6.5-8.5$^{\circ}C$ was sprayed on greenhouse roof surface with the water flow rate of 1.3 liter/min per unit greenhouse floor area, greenhouse air temperature could be dropped down to 16.5-18.$0^{\circ}C$, whlch is about 1$0^{\circ}C$ below the ambient temperature of 26.5-28.$0^{\circ}C$ at that time. The most important thing in cooling greenhouse air effectively with water spray may be obtaining plenty of cool water source like ground water itself or cold water produced by heat-pump. Future work is focused on not only analyzing the feasibility of heat pump operation but also finding the relationships between greenhouse air temperature(T$_{g}$ ), spraying water temperature(T$_{w}$ ), water flow rate(Q), and ambient temperature(T$_{o}$).

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Taxonomical Classification of Bugog Series (부곡통의 분류)

  • Song, Kwan-Cheol;Hyun, Byung-Geun;Sonn, Yeon-Kyu;Hong, Suk-Young;Kim, Yi-Hyun;Choe, Eun-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.6
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    • pp.472-477
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    • 2009
  • This study was conducted to reclassify Bugog series based on the second edition of Soil Taxonomy : A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Morphological properties of typifying pedon of Bugog series were investigated and physico-chemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Bugog series has strong brown (7.5YR 4/6) loam Ap horizon (0~22 cm), brown (7.5YR 4/4) clay loam BAt horizon (22~41 cm), strong brown (7.5YR 4/6) silty clay loam Bt1 horizon (41~59 cm), strong brown (7.5YR 4/6) silty clay loam Bt2 horizon (59~78 cm), brown (7.5YR 4/4) silty clay loam Btx1 horizon(78~90 cm), and brown (7.5YR 4/4) Btx2 horizon(90~160 cm). That occurs on swale foot slope in area of mainly granite gneiss, granite, and schist rock materials. The typifying pedon has an argillic horizon from a depth of 22 to more than 160 cm and a base saturation (sum of cations) of less than 35% at 75 cm below the upper boundary of the fragipan. That can be classified as Ultisol, not as Alfisol. The pedon has udic soil moisture regime, and can be classified as Udult. That has a fragipan with an upper boundary within 100 cm of the mineral soil surface, and keys out as Fragiudult. Also that meets the requirements of Typic Fragiudult. That has 18% to 35% clay at the particle-size control section, and has mesic soil temperature regime. Bugog series can be classified as fine silty, mixed, mesic family of Typic Fragiudults, not as fine loamy, mixed, mesic family of Typic Fragiudalfs.

Characteristics of Fish Fauna Collected from Near Estuaries Bank and Fish-way on the Bank of Naktong River (낙동강 하구둑 수역의 어류 군집구조와 어도 이용 어류)

  • Kang, Eon-Jong;Yang, Hyeon;Lee, Heung-Hun;Kim, Kwang-Sug;Kim, Chi-Hong
    • Korean Journal of Ichthyology
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    • v.24 no.3
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    • pp.201-219
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    • 2012
  • The estuaries bank of Nakdong River, Korea, was constructed in 1987 and many arguments have been under discussion on the subject of ecological impact on ecosystem during 20 years. In this context, however, it was not focused on the role of fish-way and the way of improvement to promote fish movement to complete its life history. This paper was the result of investigation on fish fauna of upper and lower part of the bank and the analysis of comparison of the fishes with those using fish-way which were installed in each side of bank as ladder type and fish gate. The authors discussed the importance of fish gate and its management base on the result. The number of fishes collected in this study for upper part of estuaries bank was 31 species, among them 71% was the pure freshwater residents indicating the characteristics of the area as a freshwater ecosystem. It was observed that 9 species of coastal fishes were found in this region including Coilia ectens and Neosalanx sp. which is anadromous to spawn. Excluding 6 freshwater fishes, 30 fish species collected in lower part of estuaries bank were coastal fishes indicating that former brackish ecosystem was changed into marine one. The freshwater fishes found in this region were restricted the appearance only in the season of discharging freshwater into the sea. The number of fishes found in fish-way was 39 species, more than that of river and coast. But only 19 species founded in fish ladder was comparable with the result of investigation on fish gate including 32 species. It was considered that the fish gate has more important role as a fish passage from the fact that only it allowed to movement of numerous number of fry of Neosalanx sp. and Engraulis japonicus. These results indicates that two-way movement system is more efficient than downward only one in estuaries bank for fish migration.

Comparison of PCR-RFLP and Real-Time PCR for Allelotyping of Single Nucleotide Polymorphisms of RRM1, a Lung Cancer Suppressor Gene (폐암 억제유전자 RRM1의 단일염기다형성 검사를 위한 PCR-RFLP법과 Real-Time PCR법의 유용성 비교)

  • Jeong, Ju-Yeon;Kim, Mi-Ran;Son, Jun-Gwang;Jung, Jong-Pil;Oh, In-Jae;Kim, Kyu-Sik;Kim, Young-Chul
    • Tuberculosis and Respiratory Diseases
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    • v.62 no.5
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    • pp.406-416
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    • 2007
  • Background: Single nucleotide polymorphisms (SNPs), which consist of a substitution of a single nucleotide pair, are the most abundant form of genetic variations occurring with a frequency of approximately 1 per 1000 base pairs. SNPs by themselves do not cause disease but can predispose humans to disease, modify the extent or severity of the disease or influence the drug response and treatment efficacy. Single nucleotide polymorphisms (SNPs), particularly those within the regulatory regions of the genes often influence the expression levels and can modify the disease. Studies examining the associations between SNP and the disease outcome have provided valuable insight into the disease etiology and potential therapeutic intervention. Traditionally, the genotyping of SNPs has been carried out using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP), which is a low throughput technique not amenable for use in large-scale SNP studies. Recently, TaqMan real-time PCR chemistry was adapted for use in allelic discrimination assays. This study validated the accuracy and utility of real-time PCR technology for SNPs genotyping Methods: The SNPs in promoter sequence (-37 and -524) of lung cancer suppressor gene, RRM1 (ribonucleotide reductase M1 subunit) with the genomic DNA samples of 89 subjects were genotyped using both real-time PCR and PCR-RFLP. Results: The discordance rates were 2.2% (2 mismatches) in -37 and 16.3% (15 mismatches) in -524. Auto-direct sequencing of all the mismatched samples(17 cases) were in accord with the genotypes read by real-time PCR. In addition, 138 genomic DNAs were genotyped using real-time PCR in a duplicate manner (two separated assays). Ninety-eight percent of the samples showed concordance between the two assays. Conclusion: Real-time PCR allelic discrimination assays are amenable to high-throughput genotyping and overcome many of the problematic features associated with PCR-RFLP.

Gene Expression Analysis of Inducible cAMP Early Repressor (ICER) Gene in Longissimus dorsi of High- and Low Marbled Hanwoo Steers (한우 등심부위 근육 내 조지방함량에 따른 inducible cAMP early repressor (ICER) 유전자발현 분석)

  • Lee, Seung-Hwan;Kim, Nam-Kuk;Kim, Sung-Kon;Cho, Yong-Min;Yoon, Du-hak;Oh, Sung-Jong;Im, Seok-Ki;Park, Eung-Woo
    • Journal of Life Science
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    • v.18 no.8
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    • pp.1090-1095
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    • 2008
  • Marbling (intramuscular fat) is an important factor in determining meat quality in Korean beef market. A grain based finishing system for improving marbling leads to inefficient meat production due to an excessive fat production. Identification of intramuscular fat-specific gene might be achieved more targeted meat production through alternative genetic improvement program such as marker assisted selection (MAS). We carried out ddRT-PCR in 12 and 27 month old Hanwoo steers and detected 300 bp PCR product of the inducible cAMP early repressor (ICER) gene, showing highly gene expression in 27 months old. A 1.5 kb sequence was re-sequenced using primer designed base on the Hanwoo EST sequence. We then predicted the open reading frame (ORF) of ICER gene in ORF finder web program. Tissue distribution of ICER gene expression was analysed in eight Hanwoo tissue using realtime PCR analysis. The highest ICER gene expression showed in Small intestine followed by Longissimus dorsi. Interestingly, the ICER gene expressed 2.5 time higher in longissimus dorsi than in same muscle type, Rump. For gene expression analysis in high- and low marbled individuals, we selected 4 and 3 animal based on the muscle crude fat contents (high is 17-32%, low is 6-7% of crude fat contents). The ICER gene expression was analysed using ANOVA model. Marbling (muscle crude fat contents) was affected by ICER gene (P=0.012). Particularly, the ICER gene expression was 4 times higher in high group (n=4) than low group (n=3). Therefore, ICER gene might be a functional candidate gene related to marbling in Hanwoo.

A Seismic Study on Muddy Sediment Deposits in the Northern Shelf of the East China Sea (동중국해 북부대륙붕에 발달한 니질 퇴적체의 탄성파 연구)

  • Choi Dong-Lim;Lee Tae-Hee;Yoo Hae-Soo;Lim Dhong-Il;Huh Sik;Kim Kwang-Hee
    • Economic and Environmental Geology
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    • v.38 no.6 s.175
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    • pp.633-642
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    • 2005
  • We present the sedimentary sequence and distribution pattern of the late Holocene muddy deposits in the northern East China Sea shelf using the high-resolution 'Chirp' profiles. The seismic sedimentary sequence overlying acoustic basement (basal reflector-B) can be divided into two depositional units (Unit 1 and 2) bounded by erosional bounding surface (mid reflector-M). The lower Unit 1 above basal reflector-H is characterized by the acoustically parallel to subparallel reflections and channel-fill facies. The upper Unit 2, up to 7 m in thickness, shows seismically semi-transparent seismic facies and lenticular body form. On the base of sequence stratigraphic concept, these two sediment units have developed during transgression and highstand period, respectively, since the last sea-level lowstand. The transgressive systems tract (Unit 1) lie directly on the sequence boundary (reflector B) that have farmed during the last glacial maximum. The transgressive systems tract in this study consists mostly of complex of delta, fluvial, and tidal deposits within the incised valley estuary system. The maximum flooding surface (reflector M) corresponding to the top surface of transgressive systems tract is obviously characterized by erosional depression. The highstand systems tract (Unit 2) above maximum flooding surface is made up of the mud patch filled with the erosional depression. The high-stand mud deposits showing a circle shape just like a typhoon symbol locates about 140 km off the south of Cheju Island with water depth of $60\~90m$. Coverage area and total sediment volume of the mud deposits are about $3,200km^2$ and $10.7\times10^9\;m^3$, respectively. The origin of the mud patch is interpreted as a result of accumulating suspended sediments derived from the paleo-Yellow and/or Yangtze Rivers. The circular distribution pattern of the mud patch appears to be largely controlled by the presence of cyclonic eddy in the northern East China Sea.

Development of Error Analysis Program for Phase-based Respiratory Gating Radiation Therapy (위상기반 호흡연동 방사선치료 시 오차 분석 프로그램 개발)

  • Song, Ju-Young;Nah, Byung-Sik;Chung, Woong-Ki;Ahn, Sung-Ja;Nam, Taek-Keun;Yoon, Mi-Sun
    • Progress in Medical Physics
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    • v.17 no.3
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    • pp.136-143
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    • 2006
  • The respiratory gating radiation therapy which Irradiates only in the stable respiratory period with analyzing the periodic motion of a reflective marker on the patient's abdomen has been applied to the precise radiation treatment in order to minimize the effect of organ motion induced by the respiration. This respiratory gating system establishes irradiation region using the amplitude-based or phase-based method. Although phase-based method Is preferred because of the stability in the real treatment conditions, it has some limits to explain the exact correlation between the marker motion and organ motion. Even when the variation of amplitude which can introduce target motion considered as an error is produced, the phase-based method has the possibility to irradiate including the error positions. In this study, the error analysis program was developed for the verification of the tumor position's variation correlated with the variation of marker's amplitude which can be occurred during a phase-based respiratory sating treatment. The analysis program was tested with a virtual treatment record file and with a record file using moving phantom which were modified considering the irregular amplitude's variation simulating the real clinical situations. In both cases, accurate discrimination of error points and error calculation were produced. When the treatment record files of a real patient were analyzed with the program, the accurate recognition and calculation of the error points were also verified. The analysis program developed in this study will be applied as a useful tool for the analysis of errors due to the irregular variation of patients' respiration during the phase-base respiratory gating radiation treatment.

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