• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.1-21
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• 2024

This study conducted surveys to identify the distribution of communities and flora according to vegetation in the coastal sand dunes of Sagye in Jeju Special Self-Governing Province, located at the southernmost tip of Korea. The survey was conducted over 20 sessions from April 2020 to October 2021. As a result of the study, physiognomy was classified into six correlated vegetation types: plant communities on the salt marsh, annual communities on a coastal drift-line, herb communities on a dune, shrub communities on a coastal dune, forest-edge communities on a dune, and artificial afforestation vegetation. The survey identified 43 communities, and a total of 212 taxa were found to be distributed among 62 families, 166 genera, 191 species, 15 varieties, 3 subspecies, and 3 forma. It was found that there were five rare plant taxa distributed in the area, including the Cymbidium macrorrhizum which was classified as an endangered Class II plant by the Ministry of Environment. Floristic target species identified by the surveys included 2 taxa for grade V, 5 taxa for grade IV, 15 taxa for grade III, 14 taxa for grade II, and 19 taxa for grade I. Climate-sensitive biological indicator species included 11 indicator and 2 candidate species, representing a high ratio of 33.3% of all indicator species and 15.4% of candidate species. Naturalized plants included 16 families, 43 genera, and 52 taxa, with a naturalization rate of 21.1% and an urbanization index of 24.5%. It is expected that these results will be widely used as data needed to prepare conservation and management measures for biodiversity in response to climate change in coastal dunes in the future.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.343-349
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• 2013

Environment-friendly agro-materials tend to be preferred to chemical insecticides recently. For this reason, many studies are conducted to develop environment-friendly insecticides containing natural materials. The purpose of this study was to assess ecotoxicity for pepper extract and cassia oil (11.5+46%, A), pepper extract and cassia oil (23+34%, B), and pepper extract and lavender oil (40+10%, C). They are expected to prevent from pests especially diamondback moth, and can be used for agro-materials. Their formulation was emusifiable concentration (EC). Target species used to assess acute toxicity were aquatic invertebrate (Daphina magna), fish (Cyprinus carpio), honeybee (Apis mellifera L.) and earthworm (Eisenia fetida). The $EC_{50}$ value of A, B, and C to aquatic invertebrate were 0.46, 1.9, 0.25 mg $L^{-1}$ respectively and these values were moderately toxic according to standard of USEPA. In case of acute toxicity test to fish, the $LC_{50}$ of A, B, and C were 1.9, 2.9, 3.8 mg $L^{-1}$ respectively. A was category II in acute toxicity of fish and not acceptable to evaluation criteria of environment-friendly agro-materials. B and C were category III and acceptable. Acute contact and oral toxicity test to honeybee were conducted and the $LD_{50}$ of A, B, and C were > 100 ${\mu}g$ a.i. $bee^{-1}$ in both of tests. It indicated they were low toxic to honeybee. In case of acute toxicity test to earthworm, $LC_{50}$ of A, B, and C were 695, 988, and 564 mg $kg^{-1}$. In conclusion, pepper extract+cassia oil 57% EC and pepper extract+lavender oil 50% EC were expected to be used for environment-friendly insecticide materials with low risk against ecosystem and contribute to developing environment-friendly agro-materials.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.265-274
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• 2002

Among many maturation indicators of growing patients, menarche and skeletal maturity are useful to assess growth and development, and the changes of the first and third finger are relatively important in hand-wrist X-rays. The objective of this study was to evaluate the relationship between menarche and the changes of the phalanx of the first and third finger and compare skeletal maturation among different malocclusion types. The sample used in this study was 29 Class 1,27 Class II and 27 Class III females whose hand-wrist X-rays had been taken with 6 month interval before the appearance of ulnar sesamoid ossification till the phalanges of the fingers were almost fused. The results were as follows. 1. There was no skeletal maturity difference among malocclusion types. 2. There was no difference in the mean chronologic age of menarche among different malocclusion types and that was $12.30\pm0.98$ years. 3. The ulnar sesamoid was observed at $10.35\pm1.01$ years, and on distal phalanx of the first finger, epiphyseal capping appeared at $11.26\pm1.04$ years and fusion at $13.12\pm1.06$ years. The epiphyseal capping on middle phalanx of the third finger was observed at $11.57\pm1.02$ years and fusion at $13.72\pm1.04$ years. 4. The timing of menarche occurred around the same time as the fusion process of distal phalanx of the first finger(p<0.001, r=0.82) and the initiation of fusion of middle phalanx of the third finger(p<0.001, r=0.78). Therefore, we can give the aid when we evaluate the growth and development of growing females seeing the changes at phalanx of the first and third finger.

• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.93-107
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• 2004

Enlow's counterpart analysis explains the complex with anatomic and developmental characteristics where craniofacial aspect of Individuals has been developed. Counterpart analysis does not compare individual measurement with the normal value from the average of majority but analyzes by comparison of values that each individual has. In this study we examined surgical changes in skeletal Class III malocclusion patients(male 40, female 40) and compared them with normal occlusion patients using counterpart analysis. The results indicated that : 1. Skeletal anterior-posterior discrepancy was relieved by shortening of the ramus width(B3). 2. The ramus alignment(R3, R4) was displaced posteriorly and the occlusal plane angle(R5) was rotated clockwise. 3. Skeletal Class III pattern was relieved in the post-operative group, but differences in the level of the cranium(R1, R2) was remaining compared to the normal occlusion patients. 4. In the comparison of surgery methods, the two-jaw surgery group presented changes In the maxillary length(A4), ramus alignment(R3, R4) and occlusal plane angle(R5) compared to the one-jaw surgery group, but the differences were not significant. In the past study about Korean skeletal Class m patients, the skeletal characteristics are upward backward rotation of the cranial base, posterior displacement of the maxilla, forward inclination of the ramus and lengthening of the mandibular body, but in this study, skeletal Class m pattern was relieved by shortening of the ramus width and maxillary advancement by orthognathic surgery, because orthognathic surgery is usually performed on limited areas in the maxilla and the mandible.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.74-83
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• 2006

Analysis of lateral cephalometric radiograph (cephalogram) has been used routinely to evaluate skeletal and dental relationships, but analysis of the lateral facial photograph has not been used frequently for evaluation of skeletal relationships. As concerns about harm of X-ray irradiation increases, this study was planned to evaluate the possibility of substituting analysis of the lateral cephalogram with analysis of the lateral facial photograph by comparing these two analyses. According to the ANB values from cephalometric analysis, subjects were divided into three groups: Class I malocclusion group (n=32). Class II malocclusion group (n=32), and Class III malocclusion group (n=31). After measurements of angles indicating horizontal and vertical relationships of the maxilla and mandible on the lateral cephalograms and photographs, differences between Class I, II and III groups were evaluated. To evaluate the similarity between two similar values in the cephalograms and photographs, t-test using standardized variable Z and correlation analysis were performed in the Class I malocclusion group. The results showed that 1) SnN'Pg' on the photograph can be used to evaluate the antero-posterior relationship of the maxilla and mandible (ANB), 2) N'-Sn/Sn-Pg' on the photograph can be used to evaluate facial convexity (NA/APg), 3) Sn-Tra-Me' on the photograph can be used as a measurement similar to FMA. In conclusion, partly substituting lateral cephalogram analysis with lateral facial photograph analysis was possible in the evaluation of the maxilla and mandible.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.1-18
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• 2016

This study was carried out to investigate the flora of the western front (Paju-Yencheon Area) of the Civilian Control Zone. Vascular plants collected in these areas were a total of 558 taxa composing of 501 species, 3 subspecies, 48 varieties and 1 forma of 330 genera under 109 families This shows that 11% of the 4,880 vascular plant species that are known to exist in Korea is distributed in the western part of the DMZ. 1 taxa of endangered species designated by the Ministry of Environment was found: the Polygonatum stenophyllum Maxim in the edge of the military operation road from Taepung observatory to Imjin river. For the floristically specific ones of the Korean floristic zones, 3 taxa of the $5^{th}$ grade, 3 taxa of the $4^{th}$ grade, 13 taxa of the $3^{rd}$ grade, 13 taxa of the $2^{nd}$ grade and 22 taxa of the $1^{st}$ grade were found. For the endemic species of Korea, 4 taxa including Cirsium setidens (Dunn) Nakai were confirmed to be distributed mostly on the slope or the cutting area. Among the collected rare plants (11 taxa), there were 1 taxa of endangered species, 4 taxa of vulnerable species and 6 taxa of least concern species. Also, 51 taxa of naturalized plants were identified and 4 taxa of ecosystem disturbance organism designated by the Ministry of Environment were identified. The urbanization index and naturalization index for all species were estimated to be 15.89% and 9.14% respectively. Our survey is expected to be considered as primary data of biological diversity and ecological axis in the DMZ and the western part of the DMZ. According to the results of this study, it is thought to be necessary to establish policies for conservation and protection of the DMZ.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.251-265
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• 1999

Various types of horizontal reference planes are used for diagnosis, treatment planning and evaluation of treatment results. But these reference Planes lack accuracy and repro-ducibility, and are mainly for Caucasian. Unlike the adult patients who have completed growth, the horizontal reference planes for growing children may change continuously during growth. Therefore this must be considered in selecting the horizontal reference plane. The purpose of this study was to Investigate the angle formed by the Sella-Nasion(SN) plane and Frankfort-Horizontal(FH) plane and evaluate the angle formed by FH plane and other horizontal reference planes in relation to different skeletal maturity and malocclusion types. 540 subjects with no orthodontic treatment history were chosen, and hand -wrist X-rays and lateral cephalometric X-rays were taken. According to SMA(Skeletal Maturity Assessment) of hand-wrist X-rays, the subjects were classified into 3 skeletal maturity groups : SMI 1-4 for group A, SMI 5-7 for group B and SMI 8-11 for group C. A second classification was made according to cephalometric analysis of lateral cephalograms. The subjects were classified into 3 malocclusion groups : Skeletal Class I, II and III malocclusion group. 10 measurements were evaluated. The results were as follows. 1. The angle formed by the SN plane and FH plane showed no difference among skeletal maturity groups, malocclusion groups, and between .sexes. 2. The angles formed by the SN plane and FH plane were $8.27^{\circ}{\pm}2.31^{\circ}$ for males and $8.59^{\circ}{\pm}2.24^{\circ}$ for females. The average value for females and males was $8.42^{\circ}{\pm}2.28^{\circ}$. 3. The angle formed by the FH plane and palatal plane was almost constant showing no difference among skeletal maturity groups, malocclusion groups, and between sexes($1.09^{\circ}{\pm}3.21^{\circ}$).

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.183-195
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• 1999

Growth and development evaluation of patients with growth potential is of great importance for orthodontic treatment planning. Timing of orthodontic intervention greatly depends on one's developmental status, thus if there is a difference in skeletal maturation among malocclusion types different treatment timing should be applied. The objective of this study was to evaluate and compare skeletal maturation among different malocclusion types. The samples used in this study was 38 Class I, 36 Class II and 33 ClassIII females aging from 8 to 10 years. Handwrist X-rays were taken with 6 month interval till 12-13 years of age. The results were as follows. 1. There was no skeletal maturity difference among different malocclusion types. 2. The hamular process of hamate was observed at $9.16{\pm}0.72$ years, pisiform bone at $9.13{\pm}0.71$ years and the ulnar sesamoid at $10.34{\pm}0.84$ years. 3. The timing of epiphyseal capping on the third finger was $10.96{\pm}0.80$ years for distal phalanx and $11.27{\pm}0.87$ years for middle phalanx, $11.12{\pm}0.85$ years for proximal phalanx of the first finger, $11.21{\pm}0.82$ years for radius and $11.62{\pm}0.85$ years for middle phalanx of the fifth finger. 4. The appearance of pisiform bone showed high correlation with appearance of hamular process of hamate(r=0.91) and ulnar sesamoid bone appearance showed high correlation with advanced ossification of hamular process(r=0.86). Timing of epiphyseal capping among different parts showed high correlation(r=0.80-0.90). 5. The shape of middle phalanx of the fifth finger showed the highest variability ($20.6\%$).

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.419-435
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• 2003

The purpose of this study was to evaluate growth changes and skeletal characteristics of Korean children with Class III malocclusions from 10 to 14 years of skeletal age. Radiographs of 60 children with Class III malocclusion and 60 normal controls were assessed. Both groups were subdivided into 6 samples according to sex and skeletal age. Skeletal age was assessed using handwrist X-rays using the Greulich and Pyle norms. The Krogman-Walker plane (occipitale-maxillon) through Sella was used as a reference plane in this study with x-axis perpendicular to the x-axis. Sir Student t-tests were conducted to compare the control group with the Class III group according to each gender a:nd age. The characteristics of Class III malocclusion group compared to the control group included shorter anterior and posterior cranial base, shorter and retrusive maxilla, forger mandible, increased molar-incisor distance, retroclined lower incisors, labially proclined upper incisors, and anteriorly located mandibular molar, smaller upper and middle facial depth, and larger lower facial depth. Landmarks representing facial depth, size of maxilla and mandible, and their AP relationship including anterior facial height indicate that growth characteristic was determined early in life. But growth Pattern of cranial base and some of the dental landmarks showed progressive divergence between Control and Class III groups with age. The position of the posterior border of the mandible was found to be significantly forward in both females and males by the age of 14 and at the anterior border in males and females at all ages. Hyperdivergent mandibular plane, changes in anterior segment of mandible, small anterior cranial base, and decrease in cranial base flexure was also noted.

• The korean journal of orthodontics
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• v.30 no.2 s.79
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• pp.197-204
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• 2000

[$K^+$]-selective ion channels were studied in excised inside-out membrane patches from human osteoblast-like cells (G292). Three classes of $K^+$channels were present and could be distinguished on the basis of conductance. Conductances were $270\pm27\;pS,\;113\pm12\;pS,\;48\pm8\;pS$ according to their approximate conductances in symmetrical 140 mM KCl saline at holding potential of -80 mV It was found that the small conductance (48 pS) $K^+$channel activation was dependent on membrane voltage. In current-voltage relationship, small conductance $K^+$channel showed outward rectification, and it was activated by the positive potential inside the membrane. In recordings, single channel currents were activayed by a negative pressure outside the membrane. The membrane pressure increased $P_{open}$ of the $K^+$ channel in a pressure-dependent manner. In the excised-patch clamp recordings, G292 osteoblast-like cells have been shown to contain three types of $K^+$ channels. Only the small conductance (48 pS) $K^+$channel is sensitive to the membrane stretch. These findings suggest that a hyperpolarizing current, mediated in part by this channel, may be associated with early events during the mechanical loading of the osteoblast. In G292 osteoblast-like cells, $K^+$channel is sensitive to membrane tension, and may represent a unique adaptation of the bone cell membrane to mechanical stress.