• Journal of Korean Society of Forest Science
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• v.77 no.3
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• pp.259-268
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• 1988

For the purpose of examining the effects of simulated acid rain on nutrient contents of plant tissues in Pintos densiflora seedlings and Forsythia koreana rooted cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College. One-year-old Pinus densiflora seedlings and Forsythia koreana cuttings were planted in the pots filled the mixed soils(nursery soil : forest soil of siliceous sandy loam=1 : 1 v/v) in the early spring of 1986. The regime of artificial acid rain, in terms of spray frequency per month and spray amount at single treatment per plot, was simulated on the basis of climatological data averaged from 30 years records. Simulated acid rain(pH 2.0, pH 4.0, and pH 5.5 as control) containing sulfuric and nutric acid in the ratio of 3 : 2(chemical equivalant basis) diluted with ground water were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season(May 1 to August 31) in 1986. The results obtained in this study were as follow : (1) As for the nitrogen contents in plant tissues, P. densiflora increased significantly in one-year-old stembranch and root tissues, and F. koreana increased significantly in leaf and root tissues, as the pH levels of acid rain decreased. (2) The available phosphate contents in root tissues of P. densiflora, and in leaf and root tissues of F. koreana were significantly decreased, as the pH levels of acid rain decreased. (3) $K_2O$, CaO and MgO contents in plant tissues were significantly decreased in the both species as the pH levels decreased. And the effects of acid rain on F. koreana were higher than those of P. densiflora. (4) Sulfur contents of plant tissues in the both species were increased at pH 2.0 treatment. There were significant differences among three acid rain treatments in leaf and root tissues of P. densiflora, and in all parts of F. koreana. (5) In the effects of simulated acid rain on the both species and the tested soils, in general, F. koreana revealed higher sensitiveness than P. densiflora, and the lower pH levels of simulated acid rain were treated, the more sharp reaction was showed.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.1
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• pp.8-17
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• 2019

Purpose: The study analyzed the prevalence of peri-implantitis and factors which may have affected the disease. Materials and methods: This study based on medical records and radiographs of 422 patients (853 implant cases) who visited Ewha Womans University Mokdong Hospital Dental Center from January 1, 2012 to December 31, 2016. Generalized estimation equations (GEE) was utilized to determine the statistical relationship between peri-implantitis and each element, and the cumulative prevalence of peri-implantitis during the observation period was obtained by using the Kaplan Meier Method. Results: The prevalence rate of peri-implantitis at the patient level resulted in 7.3% (31 patients out of a total of 422 patients), and at the implant level 5.5% (47 implants out of a total of 853 implants). Sex, GBR, guided bone regeneration (GBR) and functional loading periods had statistical significance with the occurrence of peri-implantitis. Upon analysis of the cumulative prevalence of peri-implantitis in terms of implant follow-up period, the first case of peri-implantitis occurred at 9 months after the placement of an implant, and the prevalence of peri-implantitis showed a non-linear rise over time without a hint of a critical point. Conclusion: The prevalence of peri-implantitis at the patient level and the implant were 7.3% and 5.5%, respectively. Male, implant installed with GBR and longer Functional Loading Periods were related with the risk of peri-implantitis.

• Journal of Nutrition and Health
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• v.50 no.4
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• pp.313-324
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• 2017

Purpose: The purpose of this study was to examine the association between intake of antioxidant vitamins and prevalence of metabolic syndrome (MetS) among Korean adults. Methods: A total of 614 subjects aged 30~60 years were recruited from those who received a medical checkup at a general hospital in South Korea between 2009 and 2012. Presence of MetS was determined based on criteria issued by the NCEP ATP III. Intakes of antioxidant vitamins (vitamin A, retinol, carotenoids, vitamin C, and vitamin E) were estimated by combining 3-day diet records with an antioxidant vitamin database for common Korean foods. We used multiple logistic regression analysis to assess the association between dietary intakes of antioxidant vitamins and MetS. Results: Men in the highest tertile for retinol (OR = 0.40, 95% CI = 0.23~0.71, P for trend = 0.0009), carotenoids (OR = 0.57, 95% CI = 0.32~1.00, P for trend = 0.0470), and vitamin E (OR = 0.52, 95% CI = 0.30~0.92, P for trend = 0.0190) intakes had a lower likelihood of having Mets than those in the lowest tertile. The OR of high fasting blood glucose among men in the highest tertile for vitamin A (${\mu}g$ RE: OR = 0.55, 95% CI = 0.32~0.97, P for trend = 0.0417, ${\mu}g$ RAE: OR = 0.52, 95% CI = 0.29~0.92, P for trend = 0.0211), carotenoids (OR = 0.41, 95% CI = 0.23~0.73, P for trend = 0.0036), and vitamin E (OR = 0.47, 95% CI = 0.26~0.82, P for trend = 0.0080) intakes was lower than those in the lowest tertile. In women, subjects in the highest tertile of retinol intakes had a lower prevalence of MetS than those in the lowest tertile group (OR = 0.55, 95% CI = 0.30~0.98). The OR for abdominal obesity was lower among women with the highest vitamin A (${\mu}g$ RE) intakes compared to those in the lowest tertile (OR = 0.51, 95% CI = 0.28~0.93, P for trend = 0.0293). Conclusion: These results suggest that dietary intakes of antioxidant vitamins might be associated with reduced risk of having MetS among Korean adults.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.371-381
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• 2020

The Ministry of Environment (ME) is planning to adopt in 2020 the IUCN regional Red List for "Guidelines for listing and delisting rare & endangered species and management of endangered Species System". The ME designated 377 species of vascular plants on the regional Red List. In a previous study it had been suggested that 103 species from this list are candidates for the regional Red List. With respect to a possible Red List, we assessed 59 species (after excluding 34 additional NA species and ten endemic species). These assessments indicated that 16 species are at the "threatened" level. Of those, one species is Critically Endangered, ten are Endangered, and five are Vulnerable. A further four species are classified as Near Threatened, 30 as Of Least Concern, and nine as Data Deficient. We found that most of the assessments proposed by the Ministry of Environment were not supported by scientific data, including quantitative geographic data (over 70%) in Criteria B. In order to determine the endangered species belonging to the orchid family, it is necessary to obtain records of illegal activities or data on overcollection. The current problem with the Ministry of Environment Red List has been the lack of management of scientific data on species showing a trend in decreasing population in the mid- to long-term; thus, there is a lack of critical resources for policy-makers. The ME legally designated categories and assessment, and the lack of expertise in failing to comply with the legal law by itself. The key to presenting an accurate overview of the state of Korean flora is to fill the information gaps with respect to significant geographical and taxonomical biases in the quality and quantity of data. By regularly updating the qualified data, we will be able to track the changes in the conservation status of the flora and inform the necessary conservation policies.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.226-245
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• 2019

Beopjusa Gwaebultaeng (Large Buddhist Painting), designated as Treasure No. 1259, was painted in 1766 and featured Yeorae (Buddha) at the center in the style of a single figure. It is the longest existing buddhist painting and was created by Duhun, a painter who was representative of 18th century Korean artists. His other remaining work is Seokgayeorae Gwaebultaeng (1767) in Tongdosa Temple. Considering their same iconography, they are assumed to have used the same underdrawing. Duhun had a superb ability to maintain a consistent underdrawing, while most painters changed theirs within a year. The Beopjusa painting carries significance because it was not only painted earlier than the one in Tongdosa, but also indicates possible relevance to the royal family through its records. Beopjusa Temple is also the site of Seonhuigung Wondang, a shrine housing the spirit tablet of Lady Yi Youngbin, also known as Lady Seonhui. Having been built only a year before Beopjusa Gwaebultaeng was painted, it served as a basis for the presumption that it has a connection to the royal family. In particular, a group of unmarried women is noticeable in the record of Beopjusa painting. The names of some people, including Ms. Lee, born in the year of Gyengjin, are recorded on the Bonginsa Temple Building, the construction of which Lady Yi Youngbin and Princess Hwawan donated money to. In this regard, they are probably court ladies related to Lady Yi Youngbin. The connection of Beopjusa Gwaebultaeng with the royal family is also verified by a prayer at the bottom of the painting, reading "JusangJusamJeonhaSumanse (主上主三殿下壽萬歲, May the king live forever)." While looking into the historical characteristics of this art, this study took an approach based on scientific analysis. Damages to Beopjusa Gwaebultaeng include: bending, folding, wrinkles, stains due to moisture, pigment spalling, point-shaped pigment spalling, and pigment penetration to the lining paper at the back. According to the results of an analysis of the painting pigments, white lead was used as a white pigment, while an ink stick and indigo were used for black. For red, cinnabar and minium were used independently or were combined. For purple, organic pigments seem to have been used. For yellow, white lead and gamboge were mixed, or gamboge was painted over white lead, and gold foil was adopted for storage. As a green pigment, atacamite or a mixture of atacamite and malachite was used. Azurite and smalt were used separately or together as blue pigments.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.11-16
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• 1987

With the purpose of pursuing the increase and decrease of chlorophyll a and chlorophyll b caused by application of the simulated acid rain treatment on Pinus koraiensis seedlings and Ligustrum obtusifolium cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College, during the growing season of 1985. Pinus koraiensis seeds stratified in cool and moist condition were sown on pots, and in case of Ligustrum obtusifolium, C1/1 cuttings were potted for experimental use in the early spring. The regime of artificial acid rain, based upon precipitation frequency and density, was simulated from the learning of climatological data averaged from 30 years records. The spray of acid water containing pH values of 4.0 and 2.0 was initiated from the 1st of May and ended on the 31st of August. As control, ground water was also treated at the same time. To analyse the chlorophyll content, those leaves looking representative and unaffected by other harmful agents were sampled on the 18th of September, and UV-visible spectrophotometer was used. With decrease in pH values of acid rain, the content of chlorophyll a and chlorophyll b decreased in both species. The decrease in chlorophyll a could be confirmed through statistical significance, but not in chlorophyll b. And when we discussed the chlorophyll decrease index which was explained in detail in the paper, an attention might be given to similarly decreasing values in both chlorophyll a and chlorophyll b, according as pH levels of acid rain decreased. The ratios of chlorophyll a to chlorophyll b in both species were not affected by different pH leaves of acid rain.

• Sleep Medicine and Psychophysiology
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• v.11 no.1
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• pp.37-43
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• 2004

Objective: The purpose of this paper is to study the possible differences in clinical and polysomnographic findings, depending on the presence or absence of subjective complaints of abnormal sleep behavior, in patients with RWA on polysomnography. Method: We reviewed patient records and polysomnographic data of patients referred to the Sleep Laboratory at Seoul National University Hospital from June 1996 through October 2002. We defined the manifest RBD group (n=32) as patients having both complaints of abnormal sleep behavior and RWA on polysomnography. The latent RBD group (n=20) consisted of patients who exhibited RWA on polysomnography but did not complain of abnormal sleep behavior. The clinical characteristics and polysomnographic findings between the two groups were compared and analyzed. Results: Fifty-two subjects had RWA, as detected by polysomnography (42 males and 10 females, mean age of $55.1{\pm}19.1\;years$). Subjects in the manifest RBD group were significantly older than those in the latent RBD group ($61.59{\pm}13.5$ vs. $44.70{\pm}2.76\;years$, independent t-test, p<0.01). More subjects in the manifest RBD group exhibited abnormal REM behavior on polysomnography than did subjects in the latent RBD group (81.3 vs. 50.0%, Fisher's exact test, p<0.05). No significant differences between the groups were found in the prevalence of brain disorders and primary sleep disorders, gender proportion, and sleep architecture. Conclusion: No difference in sleep architecture was found between the manifest and the latent RBD groups. Only age and the presence of abnormal sleep behavior on polysomnography differentiated the two groups. We suggest that RWA on polysomnography without complaints of abnormal sleep behavior may be early manifestation of manifest RBD. Attention to RWA on polysomnography is necessary to help prevent full-blown RBD from developing.

• Journal of the Korean earth science society
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• v.25 no.8
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• pp.774-783
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• 2004

The S wave velocity and Q$s^{-1}$ structure of the uppermost part of the soil in Nakdong Delta area have been obtained to determine the characteristics of the forementioned soil. The phase and attenuation coefficients of multichannel seismic records were inverted to obtain the S wave velocity and Q$s^{-1}$ structure of the soil. The inversion results have been compared with the borehole measurements of the area. The seismic signal of the nearest geophone from a seismic source was used as the source signal to obtain the attenuation coefficients. Amplitude ratios of the signal at each geophone to the source signal wave plotted as a function of distance for the frequency range between 10 Hz and 45 Hz. The slope of a linear regression line which fits amplitude ratio-distance relationship best for a given frequency was used as the attenuation coefficients for the frequency. The dispersion curve of Rayleigh waves and the attenuation coefficients were inverted to obtain the S-wave velocity and Q$s^{-1}$, respectively, in the uppermost 8 meter of soil layer. The borehole measurements of the area show that are two distinct layers; the upper 4 meter of silty-sand and the lower 4 meter of silty-clay. The inversion results indicate that the shear wave velocity of the upper layer is 80 m/sec and 40m/sec in the lower silty-clay layer. The spacial resolution of the shear wave velocity structure is very good down to a depth of 8 meter. The Q$s^{-1}$ in the upper silty-sand layer is 0.02 and increase to 0.03 in the lower silty-sand layer. The spacial resolution of quality factor is relatively good down to a depth of 5 meter, but very poor below the depth. In this study, the S-wave velocity is higher in the silty-clay and the Q$s^{-1}$ is smaller silty-sand than in the silty-clay. However, much more data should be analyzed and accumulated before making any generalization on the shear wave velocity and Q$s^{-1}$ of the sediments.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.893-910
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• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Pediatric Infection and Vaccine
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• v.8 no.2
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• pp.150-159
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• 2001

Purpose : We need to reconsider booster vaccination schedule of Japanese encephalitis vaccination. To do that we evaluate the long-term immunogenicity and the incidence of adverse events with inactivated mouse brain derived Nakayama Japanese encephalitis vaccine. Methods : We tested neutalizing antibody for 311 elementary school students by plaque reduction neutralizing test(PRNT) at USAMC-AFRIMS(United States Armed Forces Research Institute of Medical Science/Department of Virology). We evaluated vaccine related adverse events by spontaneous reporting prospectively among 15,487 vaccinees who were vaccinated at public health center and 2,277 elementary school students who were immunized previously by a questionnaire and school health record. Results : According to the time interval from the last booster injection of 311 children, PRNT antibody titers gradually decreased as the interval increased; 239 mIU/mL, 188 mIU/mL, 134 mIU/mL, 49 mIU/mL each at 6, 18, 30, 42 months after the last booster injection. The seropositivity rates were 98%, 99%, 95.6%, 71.4% each at 6, 18, 30, 42 months after the last booster injection. There were 21(0.13%) cases with systemic reactions among 15,487 vaccinees who had visited the hospital by prospective passive reporting system at public health center. According to the questionnaires and school health records in elementary school students, local induration and pain were 17.4% and 14.8%, respectively. Systemic reactions including fever, vomiting, rash were reported in few cases. Conclusion : Biannual booster vaccination that has been recommended so far should not be necessary. Surveillance for adverse events with inactivated mouse brain derived Nakayama vaccine should be strengthened to better assess the number of cases and reactions associated with immunization.