• Korean Journal of Veterinary Research
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• v.49 no.1
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• pp.1-8
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• 2009

The ubiquitin-proteasome mediated protein degradation pathway plays an important role in regulating both cell proliferation and cell death. Proteasome inhibitors are well known to induce apoptosis in various human cancer cell lines. We investigated the effect of combined treatment with proteasome inhibitor and TRAIL, and a possible mechanism of the enhancing apoptosis by the both treatment, on TRAIL-resistant non-small cell lung cancer. A549 cells were exposed to the N-Acetyl-Leu-Leu-Norleu-al (ALLN) as a proteasome inhibitor and then treated with recombinant TRAIL protein. In A549 cells under proteasome inhibition conditions by pretreatment with ALLN, TRAIL treatment significantly decreased cell viability compared to that ALLN and TRAIL alone treatment. Also, the both treatment induced cell damage through DNA fragmentation and p53 expression. In addition, the combined treatment of both markedly increased caspase-8 activation, especially the exposure for 2 h, and Bax expression and induced the dissipation of mitochondrial transmembrane potential in A549 cells. Taken together, these findings showed that proteasome inhibition by ALLN enhanced TRAIL-induced apoptosis via DNA degradation by activated P53 and mitochondrial transmembrane potential loss by caspase-8 activation and bax expression. Therefore, our results suggest that proteasome inhibitor may be used a very effectively chemotherapeutic agent for the tumor treatment, especially TRAIL-resistant tumor cell.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.109-113
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• 2011

The purpose of this study was to examine the potentiality of urban forest roads as an environment for enhancing physical fitness. Six male university students participated in the study as subjects. The subjects walked on an urban forest road for 30 minutes. As a control experiment, they also walked on a national park trail for 30 minutes. Subjects' heart rates were monitored during the walks to calculate the ratio of the average time their heart rates were within the target range (from 60% to 80% of the maximal heart rate) for Enhancing Physical Fitness. After the walks, images of the spaces were analyzed using the semantic differential (SD) method. During the walk on the urban forest road, subjects' heart rates were within the target range 63.3% of the time, and lower than the target range 36.7% of the time. During the control experiment on the national park trail, subjects' heart rates were within the target range only 23.3% of the time, and higher than the target range 76.7% of the time. From the spatial perception evaluation using the SD method, subjects' comfortable and natural feelings when they were on the national park trail were significantly greater than when they were on the urban forest trail, but there were no differences in terms of other SD descriptors, such as friendliness and likeability. The results of our study indicate that the urban forest road provides a good environment for walking to enhance physical fitness. Although not as close to nature as national park trails, urban forest roads offer similar natural environments and have a high potentiality for serving as leisure spaces for urban residents who seek physical activities.

• Korean Journal of Environment and Ecology
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• v.2 no.1
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• pp.50-65
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• 1988

Trail and campground deteriorations and their environmental changes of soil and vegetation were studied in Guryong district of Mt. Chiak National Park in 1988. The Widths of both the entire trail and the bare portion as the trail condition were significantly greater on the more heavily used trail. and regressions showed the significant positive relationship between slope along the trail and maximum depth of the trail($R^2$=0.35). Deterioration types of trail which had higher frequency for a total of 63 observations were rock exposure(48%), trail deepening(29%) and root exposure(27%) in the high order. And occurence of trail deterioration was considerably influenced by slope along the trail Ecological changes of soil and vegetation of trailsides were not found at a uniform tendency but could be grouped, by the types of user's disturbance. On campsites. tree damage types and their frequencies were basic as a means of which grasp the limits of user's impact. The area with damaged trees on campsite in pine forest were larger than that in mixed forest and the frequency by damage type of trees varied according to the distance from the core of campsite and to the crown layer. Water content, pH and hardness of soil. coverage of lower trees, species and individuals per 100$m^2$, basal areas of upper and middle layer of trees had significant relationship with the distance from campsite to forest. The range influenced by user's disturbance was more than 70-80m, md Staphylea bumalda, Morns bombycis, Stephanandra incisa and Securinega suffruticosa were considered as tolerant species to user's impact.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.293-301
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• 2010

The purpose of this study is to figure out visitor's attitudes for trail facilities in Gayasan National Park in order to provide the basic information for effective installation and maintenance of trail facilities. The questionnaire survey on two trails were conducted to 227 visitors on the way back home after using the trails. The use characteristics of two trails were a little different from each other, and the conditions of two trails were rated relatively high both in quantity and quality. By the evaluation of 5 types of trail facilities in Haein trail and 4 types in Baegun trail, The responses were noticeably positive about wood deck, log steps with stones and wood steps in Haein trail and about deck-type wood steps and log fences in Baegun trail from the point of three aspects; harmony with nature, resources conservation and user convenience. On the other hand it seems necessary to replace the steel steps of both trails with eco-friendly materials. So, from now on it is necessary for introducing the trail facilities in National Parks to apply the eco-friendly materials extensively and to upgrade the design aspects comprehensively of harmony with nature, resources conservation and user convenience

• Tuberculosis and Respiratory Diseases
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• v.63 no.1
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• pp.42-51
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• 2007

Background: TRAIL is a cytokine that selectively induces apoptosis in various cancer cell lines. Gefitinib is new targeted drug applied in lung cancer that selectively inhibits EGFR tyrosine kinase. However, lung cancers have shown an initial or acquired resistance to these drugs. This study examined the effect of IGF-1R and its blockade on enhancing the sensitivity of lung cancer cell lines to TRAIL and gefitinib. Methods: Two lung cancer cell lines were used in this study. NCI H460 is very sensitive to TRAIL and gefitinib. On the other hand, A549 shows moderate resistance to TRAIL and gefitinib. The IGF-1R blockade was performed using adenoviruses expressing the dominant negative IGF-1R and shRNA to IGF-1R and AG1024 (IGF-1R tyrosine kinase inhibitor). Results: The adenovirus expressing dominant negative IGF-1R(950st) induced the increased expression of defective IGF-1R on the lung cancer cell surface, and the adenovirus-shIGF-1R effectively decreased the level of IGF-1R expression on cell surface. The genetic blockade of IGF-1R by the adenovirus-dnIGF-1R and AG1024 increased the sensitivity of A549 cells to TRAIL. The reduction of IGF-1R by transduction with ad-shIGF-1R also increased the sensitivity of the A549 cells to gefitinib. Conclusion: The blockade of IGF-1R through various mechanisms increased the sensitivity of the lung cancer cell line that was resistant to TRAIL and gefitinib. However, further studies using other cell lines showing acquired resistance as well as in vivo animal experiments will be needed.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.13-21
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• 2007

The purpose of this study was to evaluate visitor and expert responsiveness for trail facilities in the Huibangsa, Yeonwhabong route of, Sobaeksan National Park in order to provide basic information for effective trail building and maintenance. The questionnaire surveys with 125 samples in visitor and 12 experts as the special panel were conducted. Evaluation results indicate statistical difference between the two groups in responsiveness for 6 types of trail facilities. In addition, 2 types of facilities, such as stone paving and boardwalk, were evaluated as the effective trail facility types. Steel bridge and steel steps may require improvement of the design consideration for with taking advantage of natural landscape.

• Korean Journal of Environment and Ecology
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• v.3 no.1
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• pp.81-94
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• 1989

Use impacts to trail and campground deteriorations and their changes of natural environment were studied in Mt. Kaya National Park in 1989. The entire width, bare width and maximum depth of trail as the trail condition were significantly greater on the more heavily used trail. Deteriorations of trail which were surveyed at the total of 51 were significantly different from those of non-deteriorated points. The changes of soil and vegetation of trailsides were not found at a uniform tendency but could be more clearly grouped by the types of user's disturbance, and use impact on trailside had reached 15m inside of forest. Percentage of area for Class 5 in campsite was about 36% and about 69% of campsite area was more severe than Class 3. Recreational activities retarded the diameter growth of trees in campsite and accelerated the different composition of species. Soil and vegetative factors adapted to understand the difference of use amount and the realm of use impact could be sorted. The realm influenced by user's disturbance was about 50m from the core of campsite. Fraxinus rhynchophylla, Rhus trichocarpa, Symplocos chinensis for. pilosa and Stephanandra incisa were considered as the tolerant species to user's impact.

• Current Research on Agriculture and Life Sciences
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• v.31 no.3
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• pp.200-208
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• 2013

The purposes of this study are developing a stress index for each individual major trail in the national parks and contribute to establishing a park management policy based on scientific analyses using the index. We collected data from 144 sections of trails in national parks, conducted the Delphi survey and factor analysis, and generated the stress index by standardizing scores of factors contributing to the stress for each trail. As aresult, total eight factors contributing to the stress were considered and four of them, i.e. the amount of visits, the effect of visits, the degree of trail destruction, and species diversity, were selected to generate the stress index. How to weigh factors was determined by their importance obtained in the second Delphi survey and the average from a 5 point Likert scale. Then, the cumulative probabilities from the standardized scores were graded into five groups. In conclusion, there were twenty trails from the six national parks including Jirisan, Bukhansan, Deogyusan, Naejangsan, Seoraksan in the first grade which gained over 80 as the stress index.

• Korean Journal of Agricultural Science
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• v.31 no.2
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• pp.87-96
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• 2004

This study concentrates on the trail of the CNU(Chungnam National University) forest. The amount of use and the pattern of damage are considered, as well as the extent of environmental damage. Finally, some managerial strategies are proposed in connection with sustainable maintenance. The trail of the university forest is composed of three sections; one is the neighborhood park and the Institute of Information Technology/Communications, the second is the Institute of Information Technology/Communications and the Dormitory, and the third section is the Dormitory and the Foreign prof's Apt. The total length of the trail is 2.6km. The daily amount of use is 1,269 visitors per day. The amount of using increased three times the amount of that in 1998. This study shows the pattern of damage of the trail in the order of root-exposure, widening, rock-exposure, deepening and the divergence in the frequency of occurrence of all these factors. Environmental damage is also graded thus: grade 3 is 27.4m, grade 4 is 0.8m, grade 5 is 1.5m, and grade 6 is 0.2m. Accordingly, some managerial strategies were proposed in connection with the sustainable trail maintenance.

• Journal of Korean Society of Forest Science
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• v.105 no.3
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• pp.315-320
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• 2016

This study was carried out to establish a management plan for urban forest trails with analysis of trail damage types and soil physicochemical properties on 3 urban forest parks in Jinju, Gyeongnam-do. We found that soil hardness was significantly higher in forest trails than forest area at 0 cm and 5 cm at a significance level of 0.05. However, we could not find any significant differences for other soil properties. For the trail damage types, the most common types were as follows: trail expansion (66%), trail erosion (59%), side road (57%), and trail boundary erosion and root exposure (41%). The results showed no difference in most of these types between the trails and forest area, indicating that the forest area might be damaged as well as the trails. Priority should be given to prepare measures that prevent soil compaction from overcrowded hikers.