• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.3
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• pp.108-118
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• 2012

To investigate the responses of yellow poplar (Liriodendron tulipifera L.) seedlings to the interactive effects of the elevated atmospheric $CO_2$ level and nitrogen addition, we measured biomass, photosynthetic pigments, photosynthesis, and the contents of nitrogen (N) and carbon (C) from the seedlings after 16 weeks of the treatments. Yellow poplar seedlings were grown under the ambient ($400{\mu}mol\;mol^{-1}$) and the elevated (560 and $720{\mu}mol\;mol^{-1}$) CO2 concentratoins with three different N addition levels (1.2, 2.4, and $3.6g\;kg^{-1}$) in the Open Top Chambers (OTC). The dry weight of the seedlings enhanced with the increased N levels under the elevated $CO_2$ concentrations and the increment of the dry weight differed among the different N levels. Photosynthetic pigment content of the yellow poplar leaves also increased with the increase of the $CO_2$ concentration levels. The effects of the N levels on the photosynthetic pigment content, however, were significantly different among the $CO_2$ levels. Photosynthetic rates were affected by the levels of $CO_2$ and N concentrations. Stomatal conductance and transpiration rates increased with increasing $CO_2$ concentration. The carboxylation efficiency of the seedlings without N addition increased under the higher $CO_2$ concentrations whereas that with N addition decreased under the elevated $CO_2$ concentrations. Nitrogen and carbon uptake in leaf, stem, and root increased with the elevated $CO_2$ concentration level and N addition. In conclusion, under the elevated $CO_2$ concentrations, physiological characteristics and carbon uptake of the yellow poplar seedling were improved and increased with N addition.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.577-594
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• 1993

The ultimate goal of periodontal therapy is the regeneration of the periodontium that have been destroyed as a result of periodontal disease. This study were done in order to determine the healing status of periodontium under Polytetrafluoroethylene and millipore fillter combined with fibrin and the effect of the guided tissue regeneration procedures were performed as follows : 1) flap operation using PTFE membrane(control group) 2) flap operation using PTFE membrane which was fixed with fibrin(experimental group 1) 3) flap operation using millipore filter which was fixed with suture(experimental group II) 4) flap operation using millipore filter which was fixed with fibrin(experimental group II) After 1, 2, 4, 8, 12 weeks, dogs were sacrificed by perfusion technique and tissue block was excised including the tooth and prepared for light microscope with H-E & Masson’s trichrome staining. The result were as follows : In control and experimental group, there is no siginificant difference on epithelial cell down growth within 1st week, but more epithelial cell downgrowth in millipore or millipore combined with fibrin group. In this experiment, there were no significant difference in new cementum and alveolar bone formation whether PTFE membrane was fixed with suture or fibrin. In control and each experimental group, bone maturation appeared in 4 weeks, bone width increased bucco-lingually in control and experimental 1 group especially. Both control group and experimental group showed mild mew cementum formation on root surface and irregular arrangement of collagen fiber at 4 weeks, that showed obvious increased cementum formation at 8 weeks, and that was observed the functional arrangement of collagen fiber between new cementum and new alveolar bone at 12 weeks.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.441-445
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• 2005

Researches on estimating national-scaled forest biomass are being carried out to quantify the carbon stock of forests with the Kyoto Protocol. In general, estimates of national-scaled forest biomass are based on forest inventory data which provides estimates of forest area, stem volume, and growth of stem by age classes. Estimates of forest biomass are, however, obtained by converting stem volumes to dry weight with stem density and thereafter to whole tree biomass with biomass expansion factors (ratios of whole tree dry weight to stem dry weight). Pinus densiflora is widely distributed and one of the most economically important timber species in Korea. The species are largely grouped into two ecotypes of Geumgang and Jungbu. Stems of Geumgang type trees are straight and high compared to those of Jungbu type trees. The objective of this study was to determine and compare stem density and biomass expansion factors fore two ecotypes of Pinus densiflora according to stand age. Stem density of both ecotypes of Pinus densora increased and biomass expansion factors of them decreased with increasing tree age. In he same age class, stem density and biomass expansion factor of Geungang type Pinus densiflora were lower than those of Jungbu type Pinus densiflora. There were statistically significant differences in stem density and biomass expansion factors between Geumgang type and Jungbu type Pinus densiflora in 0-20-year-old stands and 40-60-year-old stands. Our results suggested that the reliability of the national forest biomass inventory could be improved by applying the ecotype- and age-dependent stem density and biomass expansion factors.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.19-26
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• 1978

In order to investigate the difference of rootability between 15 clones of Populus alba${\times}$glandulosa selected based on the growth performance, rooting of cutting experiments with these 15 clones were conducted at the nursery for six years from 1970 to 1975. Cutting experiments in a temperature controlled incubator in which the temperature of the cutting bed were set to $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ were also performed. Along with these experiments air layering experiments were performed to compare with the rootabilities obtained from nursery trial. The results obtained so far could be summarized as follows. 1. The best rooting clones were 65-22-4 and 65-22-11, and the average rooting percentages of these two clones for six years were 76.7%, and 72.9% respectively. The poorest rooting clone was 66-6-8 showing average rooting percentage of 45.8%. 2. The middle class of rooting percentage was ocuppied by the clones; 66-14-29, 66-14-93, 66-25-5 and 67-6-3, and the range of their rooting percentage was 60~69% on average. 3. The rooting performances observed through the nursery, the incubator and the air layering experiments were almost the same with exception of few clones. 4. P. alba${\times}$glandulosa showed the best rooting percentage at the cutting bed of $20^{\circ}C$ 5. The most roots, i.e. 78.5% of root per cutting were developed from the bottom part of the cutting shoot. 6. Adventitious and call use roots could observe in the cuttings.

• Journal of Korean Society of Forest Science
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• v.89 no.3
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• pp.440-451
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• 2000

This study was conducted in order to provide essential data and relevant management proposal to conserve and maintain big and old trees in a rational way. For the field survey, 77 big and old trees preserved by the laws in Chollabuk-do, Korea were investigated. The study results are summarized as follows : 1. To conserve and manage big and old trees, the valuable trees have been designated as natural monument trees and protection-needed trees. There are 141 individuals of 37 species designated as natural monuments and 10,049 individuals of 102 species designated as protection-needed trees. 2. Management budget for natural monument trees was devoted at 70% from the national expenditure, but that for protection-needed trees was devoted at 98% from the local expenditure. 3. Standardized sign boards and sign stones for natural monument trees were well placed and other protection facilities such as fences, branch supports and branch holdings were established. On the other hand, management of protection-needed trees was deficient overall. 4. Problems for designation process and management of protection-needed trees could include items such as insufficient management budget, various development activities, land ownership, misjudgement of tree age and species identification, unsatisfaction of sign board placement, insufficient surgery for damaged trees, pavement around tree root system and environmental pollution around the trees. 5. In order to improve the existing management methods of big and old trees, the following schemes were suggested : the development of practical criteria for natural monument and protection-needed trees, nationwide surveys of big and old tree resources, the security of national budget, securing sufficient spaces for the tree growth, specialization of management systems, extended practices of tree form management, establishment of permanent standard signs and consideration of opinions of village residents.

• Food Science and Preservation
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• v.23 no.5
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• pp.623-630
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• 2016

Inappropriate storage of fresh-cut onions may result in losses of good quality. To understand storage conditions for shelf-life and quality of fresh-cut onions, The effect of packing type and storage temperature on the quality of fresh-cut onions was evaluated. Onions stored at $0^{\circ}C$ for 2 months were peeled off after removing root and shoot parts. Each three peeled onions were packed in a polyethylene film (PE, $50{\mu}m$) or in a polyethylene/polypropylene film (PE/PP, $100{\mu}m$) with vacuum treatment (70 cmHg) and stored at different temperatures (4, and $10^{\circ}C$) for 21 days. The following analyses were examined to evaluate the quality of fresh-cut onions: microbial population, surface color, titratable acidity and pH, respiration rate, and sensory quality. Fresh-cut onions stored at $4^{\circ}C$ showed less aerobic and coliform bacterial population than those stored at $10^{\circ}C$ during observation periods. Fungal populations of fresh-cut onions packed in PE film stored at $10^{\circ}C$ increased significantly after 13 days. E. coli was not detected in all treatments during whole storage periods. Surface colors of fresh-cut onions were not affected by packing type and storage temperature, however, color difference (${\Delta}E$) of fresh-cut onions in PE/PP film stored at $10^{\circ}C$ was significantly higher than those of other treatments. Titratable acidity of fresh-cut onions was not affected by packing type and storage temperature. However, pH of fresh-cut onions packed in PE film stored at $10^{\circ}C$ increased gradually over the whole storage period. Fresh-cut onions packed in PE film showed higher $CO_2$ and less $O_2$ concentrations at $10^{\circ}C$ than those at $4^{\circ}C$. The sensory quality of fresh-cut onions was significantly affected by packing type and storage temperature after 13 days. Particularly, vacuum treatment in PE/PP film showed better sensory quality than that of PE film package at the same storage temperature. It was concluded that vacuum treatment and storage at $4^{\circ}C$ could be effective to prolong the quality of fresh-cut onions up to 21 days.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.92-98
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• 1988

The present study was performed to find the effects of ginseng and its saponins. which is written in Chung Yao Ta Tsu Tien as anti-amnesia in its chief indication. on experimental amnesia in mice. In the step through test. ginsenoside $Rb_1\;(GRb_1)\;and\;GRg_1$ facilitated the registration of memory and antagonized the electroconvulsive shock (ECS)-induced inhibition of the retention of memory. Moreover. $GRg_1$ antagonized the EtOH-induced inhibition of the retrieval of memory. In the step down test. $GRb_1\;GRb_2\;and\;GRg_1$ antagonized the ECS-induced inhibition of the retention of memory. Moreover. $GRg_1$ antagonized the EtOH-induced inhibition of the retrieval of memory and facilitated the acquisition of short term memory. In the shuttle hox and lever press tests. they have no effects on acquisition and retrieval of memory. except $GRb_1\;GRb_1$ depressed the retrieval of conditioned avoidance response in the shuttle box test. After the end of four tests. the effects of these orally administered drugs on sedative. analgesic. antipyretic and anticonvulsant actions. and on spontaneous and exploratory movements were tested in doses of less than 500mg/kg. but they had none of these effects. Present study may indicate that $GRg_1$ had effects on the retrieval of memory and on the acquisition process of learning response. The recent research on the role of NGF for the survival. regeneration and regulation of brain in adult animals. indicated the importance of NGF on dementia and amnesia. During our research on the specificity of the neurite out growth induced by NGF. we found that the effect of NGF was potentiated by $GRb_1$ in organ cultures of chick embryonic dorsal root ganglia. Then. the effect of $GRb_1$ on neuronal cell survivalin cell culture system was studied. $GRb_1$ potentiated the NGF-mediated increase of neurofilaments in cell cultures of chick embryonic sensory and sympathetic neurons. NGF with $GRb_1$ also showed a tendency to increase the number of surviving neurons of rat embryonic cerebral cortex. NGF increased choline acetyl transferase activity in cell cultures of rat embryonic septum area neurons. but $GRb_1$ did not potentiate NGF activity in cell cultures of rat embryonic septum area neurons. Present study may indicate that $GRb_1$ plays an important role for the survival or regeneration of neurons in the brain.

• Applied Microscopy
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• v.37 no.2
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• pp.83-91
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• 2007

The present study examined the epidermal changes of adhesive disks which occur during attachment in Parthenocissus tricuspidata using scanning and transmission electron microscopy. Several adhesive disks, each covered with a bract, develop from the shoot apical meristem during early development. In the initial stage, the adhesive disks are club-shaped and their upper and lower epidermis are indistinguishable. However, in the actively growing stage, they become spherical and both epidermis are clearly differentiated into the adventitious roots. Prior to wall attachment, the adhesive disks exhibit adaxial convex and abaxial concave shapes, and electron-dense substances are abundant in the vacuoles of epidermal cells. The peripheral area of the adhesive disk is adhered first to the wall surface, while the central area is drawn inward in a vacuum-like state during attachment. As the attachment progresses and the electron-dense substances continue to discharge, the upper and lower epidermis rapidly undergo deterioration and the disks shrink considerably. At this stage, structural changes of the lower epidermis occur much faster than in the upper one. The discharged substance is accumulated on the wall surface, and this aids the attachment of adhesive disks on the wall for long periods. In this manner, the shape and structure of the adhesive disk epidermis change drastically from initial growth to the mature stage. Further, the role of electron-dense substance and shrinkage of the disk during attachment has been discussed in Parthenocissus tricuspidata.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.275-280
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• 2011

BACKGROUND: The present study was conducted to find out the suitable method for organic rice production on the basis of different seedling raising methods at nine eco-friendly agricultural units of Samgi, Mangsung, Iksan and Sungsan, Gusan of Jeollabuk-do, during 2009-10. METHODS AND RESULTS: On the basis of yield and physiological parameters, pot seeding method was found to be superior to drill seeding and broadcast seeding methods. The number of panicle, grain, the precent of ripened grains, and the 1,000 grain weight, were better in pot seeding method. Maximum yield and other attributes were recorded in rice, cultivated with seedlings raised by pot and broadcast seeding method. Number of panicle/hill and grain/panicle was 10.4% and 35.1% higher than the broadcast seeding method, respectively. Yield also showed 8.8% increase in pot seeding method as compare to broadcast seeding method. Higher grain yield was obtained when 56 hills/$3.3m^2$ of rice seedlings were used as compare to 50 hills/$3.3m^2$ raised by pot seeding method and 70 hills/$3.3m^2$ of broadcast seeding method. Lodging was minimum in seedlings raised with pot seeding method as thickness of third internode was more (9.0%) than the seedlings, raised with broadcast seeding method. Root length and dry weight also showed similar tendency i.e. 13.8% and 25.3% higher, respectively. CONCLUSION(s): Quality and grade of rice, cultivated with pot seeding method was better than broadcast seeding method. Head rice was 4.4% higher; and protein content and broken rice grown by pot seeding method were 0.4% and 1.8% lower than broadcast seeding method, respectively.

• Magazine of the Korean Society of Agricultural Engineers
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• v.11 no.2
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• pp.1651-1660
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• 1969

The purpose of this study is to find out the reasonable amount of evapo-transpiration required for the paddy rice plant during the whole growing season. So. On the basis of the experimental data concerning the evapo-transpiration form 1966 to 1968, the author obtained the follow results. 1) The leaf area index in the densely planted plo is generally higher than that in the conventionally planted one during the first half of growing season So, the coefficient of transpiration in the former plot is somewaht higher than in the latter, and the coefficient of water surface evaporation under the plant cover has the inverse relation between both plots. 2) It is unreasonable that coefficient of evapo-transpiration is applied to the calculation of the evapo-transpiration requirements of each growing stage, because a degree of variation in meteorological factors and in the thickness of the plant growth is involved in it. 3) It is most reasonable that the rate of transpiration and of the water surface evapoation is applied to the calculation of the transpirated amount and evaporated one in each growing stage, because it shows almost constant value in spite of any meteorological conditions in so far as the variety of rice, planted density and control of applying fertilizer are sanme and the disease and blight are negligible. 4) The ratio of the amount of transpiration to the weight of the whole air dried yields has the tendency of decreasing as that of the yields increases having almost constant value despite the amount of pan evaporation; and the value is about 210 when the weight of root parts is included to that the yields. 5) Although the required amount of transpiration during the whole growing season can be calculated with the above ratio, Fig. 7 showing the relation between the amount of transpiration and the weight of the yields is more reasonable and will be convinient to find it. And the requirements of water surface evaporation during the same season can also be directly found witht theweight air dried straw refering to Fig. 8.