• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.56-71
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• 1980

To study the changes of vegetational composition of each plant successional stage of Pinus densiflora forest caused by pine gall midge damage, Thecodiplosis japonensis, located in Kyonggi-do area, the middle part of Korea, four districts, Anseong, Yongin, Gwangju, and Gapyeong, were selected according to the length of insect damage duration. The forest in the Anseong district was the noninfested one selected as the check. And forests in Yongin, Gwangju, and Gapyeong were the recent]y damaged, severely damaged, and damage prolonged ones in sequence. It was considered that this order could be in concord with the gradual transition of plant successional stage. In view of temperature, precipitation and soil factors, these four districts were sited within the same environment. Four survey plots were selected from each district and the distance between them was 3~4 km. Then again four subplots were set within a plot. Through needle accumulation after insect infestation, light intensity, soil moisture content, and the amount of soil organic matter were increased and these conditions could create a favorable environment enabling the new species invasion and their growth. These were naturally closely related with the increase in quantity of Pinus densiflora defoliation. After considerable time lapse, the quantities of above mentioned factors decreased with the development of the new substitute tree species. It was found that Quercus mongolica was an excellently substitute tree species come first in this studied area. Species diversity increased to a degree at the early stage of the duration of pine gall midge damage and decreased thereafter. As the same manner, similarity index value between plots in the same district decreased to a degree and increased thereafter. This was linked admittedly with the increase and decrease of tree species and evenness. Synthesizing above mentioned results, the process of plant succession studied quantitatively by changes of relative density and relative importance value, it can be concluded that Pinus densiflora forest gives way to Genus Quercus forest in which Genus Lespedeza and Genus Rhododendron species become as subdominance species after removal of the Pinus densiflora trees damaged by pine gall midge.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.19-26
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• 2008

Purpose: In general, We discharged radioactive wastewater and sewages less than $8.1{\times}10^{-13}$ Ci/ml in a exclusive water-purifier tank. Our hospital operating three exclusive water-purifier tank for radioactive wastewater and sewages of 60 tons capacity respectively. In order to meet the criteria it need a enough decay more than 125 days per each exclusive tank. However, recently we fell into the serious situation that decay period was decreased remarkably, owing to the wastewater amount increased rapidly by enlarge the therapy ward. For that reason, in this article, I'd like to say the way that reducing of radioactive wastewater and sewages rationally. Materials and Methods: From January, 2006 to October, four hundred and two cases were analyzed. They were all hospitalized during 3 days and 2 nights. We calculated the average amount of water used (include toilet water used, shower water used, washstand water used, $\cdots$), each exclusive water-purifier tank's decay period, as well as try to search the increased factors about water-purifier tank inflow flux by re-analysis of the procedure of radioisotope therapy step by step. Results: We could increase each exclusive water-purifier tank's decay period from 84 days to 130 days through the improvement about following cause: (1) Improvement of conventional toilet stool for excessive water waste $\rightarrow$ Replacement of water saving style toilet stool (2) Prevention of unnecessary shower and wash (3) Stop the diuretics taking during hospitalization (4) Analysis of relationship between water intakes and residual dose of body (5) Education about outside toilet utilization before the administration (6) Changed each water-purifier tank's maximum level from85% to 90% Conclusion: The originality of our efforts are not only software but hardware performance improvements. Incidentally the side of software's are change of therapy procedures and protocols, the side of hardware's are replacement of water saving style toilet stool and change of each water-purifier tank's maximum level. Thus even if a long lapse of time, problem such as return to the former conditions may not happen. Besides, We expect that our trials become a new reasonable model in similar situation.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.377-388
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• 1998

Purpose : To evaluate changes in expression of cell cycle related genes during apoptosis induced in HL60 cells by X-irradiation to understand molecular biologic aspects in mechanism of radiation therapy. Material and Methods : HL-60 cell line (promyelocytic leukemia cell line) was grown in culture media and irradiated with 8 Gr by linear accelerator (6 MV X-ray). At various times after irradiation, ranging from 3 to 48 hours were analyzed apoptotic DNA fragmentation assay for apoptosis and by western blot analysis and semi-quantitative RT-PCR for expression of cell cycle related genes (cyclin A, cyclin B, cyclin C, cyclin Dl, cyclin E, cdc2, CDK2, CDK4, $p16^{INK4a}$, $p21^{WAF1}$, $p27^{KIP1}$, E2F, PCNA and Rb). Results : X-irradiation (8 Gy) induced apoptosis in HL-60 cell line. Cycline A protein increased after reaching its peak 48 h after radiation delivery and cyclin E, E2F, CDK2 and RB protein increased then decreased after radiation. Radiation induced up-regulation of the expression of E2F is due to mostly increase of Phosphorylated retinoblastoma proteins (ppRb). Cyclin Dl, PCNA, CDC2, CDK4 and $p16^{INK4a}$ protein underwent no significant change at any times after irradiation. There was not detected $p21^{WAF1}$ and $p27^{KIP1}$ protein. Cyclin A, B, C mRNA decreased immediately after radiation and then increased at 12 h after radiation. Cyclin Dl mRNA increased immediately and then decreased at 48 h after radiation. After radiation, cyclin E mRNA decreased with the lapse of time. CDK2 mRNA decreased at 3h and increased at eh after radiation. CDK4 mRNA rapidly increased at 6 to 12 h after radiation. There was no change of expression of $p16^{INK4a}$ and not detected in expressin of $p21^{WAF1}$ and $p27^{KIP1}$ mRNA. Conclusion : We suggest that entry into S phase may contribute to apoptosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of pRb protein are related with radiation induced auoptosis of HL60 cells and tosis of HL60 cells induced by irradiation. Increase of ppRb and decrease of PRb protein are related with radiation induced apoptosis of HL60 cells and this may be associated with induction of E2F and cyclinE/CDK2. These results support that $p21^{WAF1}$ and $p27^{KIP1}$ are not related with radiation induced-apoptosis.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.115-124
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• 2009

New strain needs to maintain desirable characteristics for long term when it was bred, but in lapse of time it degenerates into a bad condition. Therefore the influence of temperature on the viability and survival rates of Lentinula edodes strains were examined after cryopreservation. Also, liquid nitrogen preservation for L. edodes has been proved to be one of the most reliable method. However, a mechanical damage of strain is inevitable during cryopreservation of the fungus because the fungus is very sensitive to stress of cooling rate in the freezing process. So we tried to find out state change of L. edodes with a programmable freezer. L. edodes strains were preserved at $-20^{\circ}C$, $-80^{\circ}C$ and $-196^{\circ}C$ for 50 days. At $-20^{\circ}C$, its mycelial growth became extinct. When thawed, the growth of mycelia which were preserved at $-80^{\circ}C$ was fastest. Attempts were made to investigate viability of L. edodes strains after freezing at $-80^{\circ}C$ and $-196^{\circ}C$, respectively. As the result, more than 90% showed high survival rate of strains tested at $-80^{\circ}C$ and $-196^{\circ}C$. Mycelial growth between apical and basal parts of colony after freezing preservation for 50 days was compared. At apical and basal parts, the survival rates showed 100% at $-80^{\circ}C$, but 98% and 94% at $-196^{\circ}C$, respectively. We confirmed that the ice crystal formation temperatures of L. edodes strains were $-6.0^{\circ}C$ for Sanlim 1, $-5.5^{\circ}C$ for the Sanlim 2, $-4.0^{\circ}C$ for the Sanlim 3 and $-15.5^{\circ}C$ for the Sanzo 302. These results indicated that L. edodes strains showed completely different responses to the ice crystal formation. We knew the fact that even the same species, especially L. edodes, they displayed completely different responses to the same freezing condition. Also, this has nothing to do with the connection between temperature type and freezing point. And a protocol was tried to minimize state change of L. edodes strains using programmable freezer when they are frozen, but it was not effective on them.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.159-166
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• 1999

This study was conducted to investigate the effects of application of the dolomite particle and the shell powder on soil characteristics, dry matter yield and nutritive value of forages in loam soil at the experimental field of National Livestock Research Institute, Suwon, from 1994 to 1996. Application treatments were control, lime, dolomite 0.5, 2.0, 4.0mm, and shell powder in mixed pasture. Rate of dust occurrence was greatly decreased according to dolomite application and the dissolving rate in soil was highest in shell powder application among treatments. Although there was no significant difference, average dry matter yield of forages for 3 years was slightly increased with the application of lime, shell powder, dolomite 0.5mm, 4.0mm, 2.0mm and control in order. Both Ca and Mg contents of forages were no differences among treatments in 1994. However, all treatments were higher than those of control in 1995. And K and Na contents of forages were no differences among treatments. Lime requirement was greatly increased from 2,630 to 6,150kg per ha with the lapse of time. Although soil hardness was optimum level at first, it was likely to become hard little by little after treatments. Solid phase of soil was lowered a little except for control. Organic matter and available $P_2O_5$ contents of soil were highest in shell powder application among treatments, and K, Ca and Mg contents of soil were no differences among treatments. Ca content was increased a little in 1995, but decreased a little in 1996 compared to that of soil before treatments in 1994. AIso, Mg content was lowered than that of soil before experiment in 1995 and 1996. The results demonstrated that use of dolomite and shell powder as lime substitutes could be reduced dust problem and coast pollution as well as soil improvement. Therefore, it is desirable to apply the dolomite and the shell powder every 3 years in loam soil.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.121-134
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• 1976

There are many evidences that vaiious plant pathogenes were introduced with imported plants and agricultural productsrfrom foreign countries and caused heavy losses of domestic economic plants, ever since the early twentieth century when our country began to trade plants and agricultural products with foreign countries. There are many ways that foreign plant pathogenes have been introduced into our country, but the main route is considered to be imported plants and agricultural products contaminated with plant pathogenes. Plant quarantine which prevent effectively introduction of plant pathogenes from abroad was practiced for the first time in our country in 1912, and that is relatively earlier activity in the history of plant quarantine of the world. Several plant pathogenes have been introduced into our country even after plant quarantine had been practiced. Particularly for about 15 years, from the 2nd World War to 1961 when the law of Plant Protection was enacted and practical works of plant quarantine was reoperated, Korean agriculture was opened to various foreign plant pathogenes as a lapse period of plant quarantine in our country. Introduced plant pathogenes are, for the most part, from Japan because of depending upon Japan in the foreign trade of plants and agricultural products of our country. As present plant quarantine is required more exactness and rapidness, reasonable organization of quarantine system including more trained quarantine specialists, modernized facilities and introduction of improved quarantine techniques are necessary. Reasonable organization and improvement of plant quarantine system are important not only for protection of korean agriculture to plant pathogenes possible to be introduced from foreing countries, but also for increasing and stabilization of export of plants and agricultural product of our country.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.101-114
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• 2008

Pressurized grouting is a common technique in geotechnical engineering applications to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressurized grouting has been applied to a soil-nailing system which is widely used to improve slope stability. Because interaction between pressurized grouting paste and adjacent ground mass is complicated and difficult to analyze, the soil-nailing design has been empirically performed in most geotechnical applications. The purpose of this study is to analyze the ground behavior induced by pressurized grouting paste with the aid of laboratory model tests. The laboratory tests are carried out for four kinds of granitic residual soils. When injecting pressure is applied to grout, the pressure measured in the adjacent ground initially increases for a while, which behaves in the way of the membrane model. With the lapse of time, the pressure in the adjacent ground decreases down to a value of residual stress because a portion of water in the grouting paste seeps into the adjacent ground. The seepage can be indicated by the fact that the ratio of water/cement in the grouting paste has decreased from a initial value of 50% to around 30% during the test. The reduction of the W/C ratio should cause to harden the grouting paste and increase the stiffness of it, which restricts the rebound of out-moved ground into the original position, and thus increase the in-situ stress by approximately 20% of the injecting pressures. The measured radial deformation of the ground under pressure is in good agreement with the expansion of a cylindrical cavity estimated by the cavity expansion theory. In-situ test revealed that the pullout resistance of a soil nailing with pressurized grouting is about 36% larger than that with regular grouting, caused by grout radius increase, residual stress effect, and/or roughness increase.

• Journal of Climate Change Research
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• v.1 no.1
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• pp.31-50
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• 2010

The Arctic climate change for the Last Glacial Maximum(LGM) occurred at 21,000 years ago (21ka) was investigated using simulation results of atmosphere-ocean coupled models from the second phase of the Paleoclimate Modelling Intercomparison Program(PMIP2). In the analysis, we used seven models, the NCAR CCSM of USA, ECHAM3-MPIOM of German Max-Planxk Institute, HadCM3M2 of UK Met Office, IPSL-CM4 of France Laplace Institute, CNRM-CM3 of France Meteorological Institute, MIROC3.2 of Japan CCSR at University of Tokyo, and FGOALS of China Institute of Atmospheric Physics. All the seven models reproduces the Arctic climate features found in the present climate at 0ka(pre-industrial time) in a reasonable degree in comparison to observations. During the LGM, the atmospheric $CO_2$ concentration and other greenhouse gases were reduced, the ice sheets were expanded over North America and northern Europe, the sea level was lowered by about 120m, and orbital parameters were slightly different. These boundary conditions were implemented to simulated LGM climate. With the implemented LGM conditions, the biggest temperature reduction by more than $24^{\circ}C$ is found over North America and northern Europe owing to ice albedo feedback and the change in lapse rate by high elevation. Besides, the expansion of ice sheets leads to the marked temperature reduction by more then $10^{\circ}C$ over the Arctic Ocean. The temperature reduction in northern winter is larger than in summer around the Arctic and the annual mean temperature is reduced by about $14^{\circ}C$. Compared to low mid-latitudes, the temperature reduction is much larger in high northern altitudes in the LGM. This results mirror the larger warming around the Artic in recent century. We could draw some information for the future under global warming from the knowledge of the LGM.

• Journal of Preventive Medicine and Public Health
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• v.49 no.2
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• pp.80-96
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• 2016

Recently, a series of lawsuits were filed in Korea claiming tort liability against tobacco companies. The Supreme Court has already issued decisions in some cases, while others are still pending. The primary issue in these cases is whether the epidemiological evidence submitted by the plaintiffs clearly proves the causal relationship between smoking and disease as required by civil law. Proving causation is difficult in tobacco lawsuits because factors other than smoking are involved in the development of a disease, and also because of the lapse of time between smoking and the manifestation of the disease. The Supreme Court (Supreme Court Decision, 2011Da22092, April 10, 2014) has imposed some limitations on using epidemiological evidence to prove causation in tobacco lawsuits filed by smokers and their family members, but these limitations should be reconsidered. First, the Court stated that a disease can be categorized as specific or non-specific, and for each disease type, causation can be proven by different types of evidence. However, the concept of specific diseases is not compatible with multifactor theory, which is generally accepted in the field of public health. Second, when the epidemiological association between the disease and the risk factor is proven to be significant, imposing additional burdens of proof on the plaintiff may considerably limit the plaintiff's right to recovery, but the Court required the plaintiffs to provide additional information such as health condition and lifestyle. Third, the Supreme Court is not giving greater weight to the evidential value of epidemiological study results because the Court focuses on the fact that these studies were group-level, not individual-level. However, group-level studies could still offer valuable information about individual members of the group, e.g., probability of causation.

• Parasites, Hosts and Diseases
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• v.29 no.3
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• pp.279-292
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• 1991

The immune response to sheep red blood cell (sRBC) was monitored in the mice infected with Ascaris strum or Trichinella spiralis. The effects of the infection with T. spiralis or the injection with cyclophosphamide (CY) as an immunosuppression agent prior to challenge infection with the embryonated eggs of A. suum were monitored in mice by means of the level of infection with A. strum and cellular and humoral immune response to sRBC. following the oral administration of 1, 000 eggs of A. suum to mice, delayed-type hypersensitivity (DTH) and rosette-forming rate were gradually decreased and reached to the lowest levels at the 5th week and 6th week postinfection, respectively, and then returned to normal at the loth week. The hemagglutinin (HA) and hemolysin (HE) titers were gradually elevated and reached to peak at the 3rd week postinfection, and then returned to normal level. The appearance ratios of the eosinophils and mast cells were in peak at the 4th week and the 2nd week postinfection, respectively. Meanwhile the harvest ratio of A. suum larvae from the liver and lungs was 21.97% at the 1st week postinfection. Following the oral administration of 300 T. spiralis infective larvae, DTH and rosette-forming rate were gradually decreased with the lapse of time and reached the lowest values in the 30th and 21st day of postinfection, and then slightly increased and transiently decreased in the 70th and 80th day of postinfection, respectively. HA and HE titers were the lowest in the 21st and 90th day, whereas the ratios of eosinophils and mast cells were the highest on the 40th and 14th day posti nfecti on, ruts petit i vela. Following the intraperitoneal injection of CY, the body weight, the spleen weight, DTH, rosette-orming ratio, HA and HE titers, the number of WBC and the ratio of the mast cell were predominantly decreased in the 5th day, and then returned to the same value of the 1st day postinjection. The ratio of eosinophils was gradually decreased following to advance of days. At the 1st, 5th and loth days after intraperitoneal injection of CY of 400 mg/kg, a dose with 1, 000 eggs of A. suum was administered orally to mice, and harvest rate of the larvae at the 7th day postadministration was 7.07% in the 1st day, 14.94% in the 5th day, 10.1% in the loth day, 8.02% in control group. The effect of prior infection with infective larvae of T. spiralis upon immunological sequelae of a challenge infection of mice with embryonated eggs of A. suum in 30 or 70 days interval was checked. On the 37th day of prior infection with T. spiralis, that was the 7th day with A. suum postinfection, DTH and rosette-forming rate were drastically decreased, but the ratio of mast cells was highly increased and the ratio of eosinophils, HA and HE titers were fairly increased. On the other hand, the rate of larvae harvest was 9.3% in experimental group in contrast with 22.18% in control group. Meanwhile the effect of immune response to sRBC was similar to that of the former, but DTH and rosettt-forming rate were greatly decreased in the 77th day after prior infection with the 7th day after challenge infection in compariton with control. At that time, Ascaris larvae were harvested 8.3% in experimental group in comparison with 10.5% in control group.