• Journal of Periodontal and Implant Science
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• v.53 no.4
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• pp.248-258
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• 2023

Purpose: This study aimed to characterize the early stages of periodontal disease and determine the optimal period for its evaluation in a mouse model. The association between the duration of ligation and its effect on the dentogingival area in mice was evaluated using micro-computed tomography (CT) and histological analysis. Methods: Ninety mice were allocated to an untreated control group or a ligation group in which periodontitis was induced by a 6-0 silk ligation around the left second maxillary molar. Mice were sacrificed at 1, 2, 3, 4, 5, 8, 11, and 14 days after ligature placement. Alveolar bone destruction was evaluated using micro-CT. Histological analysis was performed to assess the immune-inflammatory processes in the periodontal tissue. Results: No significant difference in alveolar bone loss was found compared to the control group until day 3 after ligature placement, and a gradual increase in alveolar bone loss was observed from 4 to 8 days following ligature placement. No significant between-group differences were observed after 8 days. The histological analysis demonstrated that the inflammatory response was evident from day 4. Conclusions: Our findings in a mouse model provide experimental evidence that ligature-induced periodontitis models offer a consistent progression of disease with marginal attachment down-growth, inflammatory infiltration, and alveolar bone loss.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.2
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• pp.135-145
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• 2020

Wave observation is widely used to direct observation method for observing the water surface elevation using wave buoy or pressure gauge and remote-sensing wave observation method. The wave buoy and pressure gauge can produce high-quality wave data but have disadvantages of the high risk of damage and loss of the instrument, and high maintenance cost in the offshore area. On the other hand, remote observation method such as radar is easy to maintain by installing the equipment on the land, but the accuracy is somewhat lower than the direct observation method. This study investigates the data quality of MIROS Wave and Current Radar (MWR) installed at Dokdo and improve the data quality of remote wave observation data using the wave buoy (CWB) observation data operated by the Korea Meteorological Administration. We applied and developed the three types of wave data quality control; 1) the combined use (Optimal Filter) of the filter designed by MIROS (Reduce Noise Frequency, Phillips Check, Energy Level Check), 2) Spike Test Algorithm (Spike Test) developed by OOI (Ocean Observatories Initiative) and 3) a new filter (H-Ts QC) using the significant wave height-period relationship. As a result, the wave observation data of MWR using three quality control have some reliability about the significant wave height. On the other hand, there are still some errors in the significant wave period, so improvements are required. Also, since the wave observation data of MWR is different somewhat from the CWB data in high waves of over 3 m, further research such as collection and analysis of long-term remote wave observation data and filter development is necessary.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.685-690
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• 2000

Caliroa carinata (Zombori) has heavily damaged the forests of Quercus mongolica in Sangju, Kyongbuk, Korea since 1996. However, information on the ecology and control of this pest was badly scarce. Thus we tried to study the ecology and chemical control of the sawfly through this study. Caliroa carinata is one generation per year. The adult sawflies emerged from June 8 to July 5 with peak at June 18. A female adult laid 11 eggs in rows on the backside of a leaf along the midribs and larger veins. Larvae have six instars, and the developmental period required to complete the larval stage was 19 days and 17 days at temperatures of $20^{\circ}C$ and $25^{\circ}C$, respectively. Each larval stage required 2-4 days to complete the development. The sawfly mostly preferred Quercus mongolica and Q. dentata, while avoiding Q. variabilis. Such insecticides as Tebufenozide, Flufenoxuron, Etofenprox, and Fenitrothion were sprayed on host plant leaves infected with test larvae in order to study the mortality. After 3 days of insecticide treatments, the mortalities were thoroughly examined. All insecticides showed higher than 95% of mortalities. Control values were also higher than 93%. The optimal season of insecticide application for pest control was estimated from late June to early July.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.215-220
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• 2017

This study was conducted to improve the insufficiency of fruit vegetable grafting system developed by National Institute of Agricultural Sciences, Rural Development Administration. When the rotary blade cut the stem of scions and rootstocks, the grafting failure at curved cutting surfaces happened. The cutting depth of a tomato seedling by a rotated cutter was calculated 0.11 mm even when the cutting arm length and the maximum stem diameter were 50 mm and 5 mm, respectively. Mathematical analysis and high-speed photography showed that there was no problem by cutting in straight the stem of scions and rootstocks. The compression test of seedling stems to design the optimal shape of gripper showed that stems were not completely restored when they were compressed above 0.8 mm and 0.6 mm in case of rootstocks and scion, respectively. This study found that the bending angle of stem of tomato seedlings at the grafting period was 10 degree on average. The optimal gripper finger was the edge finger type which could be precisely set center point by adjusting the distance between fingers. In addition, it was found that most of seedling could be grasped without damage when the finger-to-finger distances is set to 2.5 mm for scion and 3.0 mm for rootstocks and finger are coated by 1 mm-thick flexible material.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.293-305
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• 2020

This experiment was aimed to identify concentrations of mineral nutrients in leaf lettuce (Lactuca sativa) grown on hydroball aquaponics and in the water for growing fish by conducting two experiments. The experiment I (Expt. I) was conducted with 12 fishes (F12) with and without filter, hydroball and plants (H12 (12 fishes, hydroball), FHP12 (12 fishes, filter, hydroball, 6 plants) and HP12 (12 fishes, hydroball, 6 plants)), and the experiment II (Expt. II) was with and without plants (FH15 (15 fishes, filter, hydroball), FHP15 (15 fishes, filter, hydroball, 6 plants)). The pH level in the water of all the treatments was decreased during the growing period, and the pH and EC of the water were lower in all the treatment with plants than those without plants in both Expt. I and Expt. II. When compared with adequate nutrient concentrations for hydroponics, nitrate nitrogen (NO₃-N) and phosphorus (P) concentrations in the fish growing water were higher under the FHP15 treatment in Expt. II; however, potassium (K), calcium (Ca), and magnesium (Mg) were only 16, 49, and 82% of hydroponics, representatively, and iron (Fe) was not detected. The fresh weight of lettuce harvested from the FHP15 treatment was 38 g, only a 30% of marketable lettuce yield. The T-N and P contents of the leaf tissue grown under the FHP15 treatment were close to the optimal level; however, the K, Ca, and iron (Fe) contents were less than the optimal with no deficiency symptom.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.423-428
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• 2014

This study was performed to identify optimal harvesting time of ginseng seeds and to examine the effect of $GA_3$ treatment for improvement of seed stratification rate. Ginseng seeds harvested from Land race, Chunpoong and Yunpoong cultivar in July 20 were tested for stratification rate. It was shown that stratification rates of land race, Yunpoong and Chunpoong cultivar were 94.1%, 93.1%, and 82.6%, respectively. Seeds of Chunpoong cultivar harvested 10-15 days later showed a comparable stratification rate to that of Land race, indicating that late harvest of Chunpoong seeds is beneficial for the increase of stratification rate. The higher stratification rate was found in mature seeds (92.3%) than immature seeds (37.8%), both of which were harvested in July 20. Stratification rate of mature seeds harvested in July 15 was 87.5%, demonstrating optimal harvesting time of ginseng seeds with higher stratification rate is after mid-July. An exponential growth of endosperms of ginseng seeds was observed from early June to mid-June and then slow growth was observed. There was no obvious growth of embryos from fertilization to mid-August. After the this time, embryos quickly grew until late October. Thus, appropriate stratification control is essential during the period (from early September to late October) in order to optimize embryo growth and development. While no increase of stratification rate was observed in seeds treated with 50 ppm of $GA_3$, significant increases were observed in seeds treated with 100 ppm of $GA_3$. At this concentration of $GA_3$, the stratification rate of Land race, Chunpoong and Yunpoong cultivar was 95.0%, 95.3%, and 96.5%, respectively.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.66-77
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• 2019

The present study investigated pine trees, which forms a major plantation species in Korea, with the objective of improving the survival rate of pine trees after planting. Growth responses and characteristics were assessed by controlling the level of fertilizer application, which is a basic controlling the growth of pine seedlings, to identify the optimal fertilization treatment. Pine tree seedlings were grown in 104 containers and were examined 8 weeks after planting. Stem height and were measured at 4-week intervals. In terms of fertilization treatment for 1-0 pine seedlings, the treatment group with gradually-increasing fertilizer concentration ($500{\rightarrow}1000{\rightarrow}1000{\rightarrow}1000mg{\cdot}L^{-1}$) had the biggest increase in stem height and diameter at the root. The survey results indicated that the increased concentration treatment group and the gradually-increasing concentration treatment group had more growth compared with that in the fixed concentration treatment group. The gradually-increasing concentration treatment group ($500{\rightarrow}1000{\rightarrow}1000{\rightarrow}1000mg{\cdot}L^{-1}$) had the highest total dry matter production. Nine weeks after fertilization, the tips of the pine leaves turned yellow in the fixed concentration treatment group ($3000mg{\cdot}L^{-1}$). The same phenomenon was observed in the treatment group in which the concentration was increased to $2000mg{\cdot}L^{-1}$, and in the gradually-increasing concentration treatment group, when the concentration was raised up to $2000mg{\cdot}L^{-1}$. We concluded that the optimal fertilization conditions for producing healthy pine 1-0 seedlings involve fertilizing once a week with Multifeed 19 at $500mg{\cdot}L^{-1}$ during the seedling period, Multifeed 19 at $1000mg{\cdot}L^{-1}$ during the rapid growth period, and Multifeed 32 at $1000mg{\cdot}L^{-1}$ during the maturation period.

• KSBB Journal
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• v.23 no.4
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• pp.317-322
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• 2008

The Biochemical Oxygen Demand(BOD) is one of important parameters for the most widely used method of organic pollution in wastewater and wastewater treatment effluent. As the conventional BOD test needs 5-day long incubation period, it is thus incompatible with real time control of wastewater treatment plant. To resolve this problem, in the present study an on-line Dissolved Oxygen(DO) monitoring system was used to observe the transient change of dissolved oxygen concentration in livestock wastewater. The system was composed of BOD sensor, amplifier and computer. It was observed that the concentration of the microorganism in the livestock wastewater was relatively constant during the growth period of initial one hour, which allowed the assumption of the constant Oxygen Uptake Rate(OUR) within one hour of measurement. It was thus concluded that the present scheme provided a protocol for automatic measurement of BOD in livestock wastewater, which can be applicable to optimal control of livestock wastewater treatment plant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1229-1236
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• 2009

This study was performed to examine the quality characteristics of the curd yogurt with different contents (0.5$\sim$2.0% (w/v)) of cherry powder (obtained from freeze-dried fruit of Prunus serrulata L. var. spontanea Max. wils.). Yogurt was fermented with two kinds of lactic acid bacteria (Streptococcus thermophilus, Lactobacillus bulgalicus) at $40^{\circ}C$ for 18h. During the period of 14 days of storage ($4^{\circ}C$, 14 days), acid production (pH and titratable acidity) of the yogurts increased significantly with the addition of cherry powder. The sugar content of the yogurts prepared with cherry powder increased but cherry powder yogurts presented lower viscosity values than the control. Hunter color values, lightness (L) and yellowness (b) of yogurt colors decreased as the concentration of cherry powder increased, whereas the redness (a) increased. Lactic acid bacteria of yogurts increased with the addition of cherry powder and all samples had increasing levels of lactic bacteria over the storage period. The sensory properties, such as flavor, taste, viscosity, and overall acceptability, of the yogurts containing the 1.0% cherry powder were superior to the control sample. Consequently, the optimal quality achieved in these experiments was yogurt with 1.0% cherry powder added.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.125-134
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• 2008

Purpose: Bone morphogenetic protein (BMP) is a potent differentiating agent for cells of the osteoblastic lineage. It has been used in the oral cavity under a variety of indications and with different carriers. However, the optimal carrier for each indication is not known. This study evaluated the bone regenerative effect of rhBMP-2 delivered with different carrier systems. Materials and Methods: 8 mm critical-sized rat calvarial defects were used in 60 male Sprague-Dawley rats. The animals were divided into 6 groups containing 10 animals each. Two groups were controls that had no treatment and absorbable collagen membrane only. 4 groups were experimentals that contained rhBMP-2 only and applied with absorbable collagen sponge($Collatape^{(R)}$), $MBCP^{(R)}$, Bio-$Oss^{(R)}$ each. The histological and histometric parameters were used to evaluate the defects after 2- or 8-week healing period. The shape and total augmented area were stable in all groups over the healing time. Results: New bone formation was significantly greater in the rhBMP-2 with carrier group than control group. rhBMP-2/ACS was the highest in bone density but gained less new bone area than rhBMP-2/$MBCP^{(R)}$ and rhBMP-2/Bio-$Oss^{(R)}$. The bone density after 8 weeks was greater than that after 2 weeks in all groups. However, rhBMP-2 alone failed to show the statistically significant difference in new bone area and bone density compared to control group. Also $MBCP^{(R)}$ and Bio-$Oss^{(R)}$ particles remained after 8 weeks healing period. Conclusion: These results suggest that rhBMP-2 with carrier system is an excellent inductive agent for bone formation and we can use it as the predictable bone tissue engieering technique. Future study will likely focus on the kinetics of BMP release and development of carriers that is ideal for it.