• Journal of Preventive Medicine and Public Health
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• v.22 no.1 s.25
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• pp.125-135
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• 1989

This paper was carried out to study on correlation between mentally retardation and lead and zinc. The subjects were 297 mentally retarded children: 132 of Bomyung special school and Sunmyung, which were located in Taegu city of Korea. The former had their parents but the latter had not. The control group 63 children were randomly seleted from the Dong-in primary school near to Medical School of Kyungpook National University. Atomic absorption spectrophotometer, model IL-551 connected with CTF atomizer(IL. 655) was used for the analysis of lead and zinc. The mean value of lead in hair of mentally retarded children was $14.97{\pm}3.71ppm$ which is significantly higher than that of control group, $11.36{\pm}2.83ppm$. But the content of zinc was not significant in both groups. In the lead there was no significant correlation to age but significant negative correlation to IQ. Zinc showed significant correlation to age but not to IQ. Among the handicapped children, no signigicant correlation between orphan group and non orphan group. Handicaps of mentally-retarded children were speech impairment, emotional disturbance, double and triple handicaps, sensory impairment and abnormal dietary patterns. There were significantly higher contents of lead compared with normal group, except the latter two groups. The disease conditions of mentally retarded children were mongolism, autism, cerebral palsy, epilepsy and microcephaly. In comparing with mongolism, significant difference were existent only on the cerebral palsy and group of unknown etiology. We attempted to divide their past history into external etiology and internal etiology, but could not find significant difference. In view of the whole results, the relationship between mentally-retarded children and lead was presumed to be the early time exposure rather than long interval exposure during growth and the contact opportunity was considered important subject in maternal and child health care.

• Research in Plant Disease
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• v.21 no.3
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• pp.201-207
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• 2015

This study was conducted to establish a simple mass-screening method for resistant melon to Fusarium wilt caused by Fusarium oxysporum f. sp. melonis (FOM). Root-dipping inoculation method has been used to investigate resistance of melon plants to Fusarium wilt. However, the inoculation method requires a lot of labor and time because of complicate procedure. To develop a simple screening method on melon Fusarium wilt, occurrence of Fusarium wilt on susceptible and resistant cultivars of melon according to inoculation method including root-dipping, soil-drenching, tip, and scalpel methods was investigated. Scalpel and tip methods showed more clear resistant and susceptible responses in the melon cultivars than root-dipping inoculation method, but tip method represented slightly variable disease severity. In contrast, in the case of soil-drenching inoculation method, disease severity of the susceptible cultivars was very low. Thus we selected scalpel method as inoculation method of a simple screening method for melon Fusarium wilt. By using the scalpel inoculation method, resistance degrees of the cultivars according to incubation temperature after inoculation (25 and $30^{\circ}C$) and inoculum concentration ($1{\times}10^6$ and $1{\times}10^7conidia/ml$) were measured. The resistance or susceptibility of the cultivars was hardly affected by all the tested conditions. To look into the effectiveness of scalpel inoculation methods, resistance of 22 commercial melon cultivars to FOM was compare with root-dipping inoculation method. When the melon cultivars were inoculated by scalpel method, resistance responses of all the tested cultivars were clearly distinguished as by root-dipping method. Taken together, we suggest that an efficient simple mass-screening method for resistant melon plant to Fusarium wilt is to sow the seeds of melon in a pot (70 ml of soil) and to grow the seedlings in a greenhouse ($25{\pm}5^{\circ}C$) for 7 days, to cut the root of seedlings with a scalpel and then pour a 10 ml-aliquot of the spore suspension of $1{\times}10^6conidia/ml$ on soil. The infected plants were cultivated in a growth room at 25 to $30^{\circ}C$ for about 3 weeks with 12-hr light a day.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.3
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• pp.145-160
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• 1979

The effects of organic material application on soil physical properties were reviewed in relation to soil productivity. The organic matter contents and soil physical properties of the cultivated land in Korea were summarized and the effects of organic matter were compared in terms of land uses and soil types. Soil physical properties related to crop yield potential, such as soil aggregation, permeability, water holding capacity, erodibility, and compactibility, were used in evaluating the effects of organic materials as a soil physical amendment. The benefical effects of organic matter addition on soil physical conditions include (1) better aeration and increased infiltration in silty and clayey soils, (2) increased water holding capacity and moisture availability in sandy soils, (3) decreased soil erodibility, and (4) increased resistance to compaction. It is, therefore, concluded that continuous application of organic materials could greatly improve the various soil physical properties and favor the growth and yield of crops. A high rate of organic matter addition could contribute to reducing not only the soil erosion on sloping land, but also the possible detrimental effect of farm mechanization. In general, the effects of organic matter on soil physical improvement were estimated to be much higher in upland than in paddy. Organic matter would have a more pronounced effect on low productive lands such as heavy clayey or sandy soils and newly reclaimed soil. The optimum level of soil organic matter content was estimated to be about 3.0 to 3.5% for the best soil physical condition. Since the organic matter contents of the cultivated lands in Korea are much lower than optimum level, it would be desiable to use more organic materials to soil for the increase of soil productivity, continuation of stabilized high productivity and soil erosion control.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.3
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• pp.207-216
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• 2010

Individual differences of ozone ($O_3$) resistance for seed production, seed germination and seedling development were examined in this study. Five in each healthy and damaged trees of Pinus thunbergii growing in air polluted area for 12 years were chosen based on visible foliar injury and growth. The cones of P. thunbergii, which were collected from healthy and damaged trees, were analyzed for physical characteristics and seeds from the cones were used to test germination percentage under $O_3$ treatment. The germinated seeds were continuously exposed to $O_3$ treatment and the lipid peroxidation and activities of antioxidative enzymes were determined for both seeds and seedlings. The $O_3$ treatment for seed germination and seedling development were conducted at three conditions: control, 150 ppb and 300 ppb of $O_3$. The non-treated seeds from the damaged trees showed 21.6% lower germination than those from the healthy ones. On the $O_3$ treatment of 300 ppb, seed germination decreased approximately 10% for the healthy trees and 19% for the damaged trees compared to that on the control. The seeds from the healthy trees showed significantly higher activities of superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) than those from the damaged trees. The activities of GR, ascorbate peroxidase (APX), and CAT decreased along with the increasing $O_3$ concentration in two tree grades. Malondialdehyde (MDA) content of seeds was not influenced by $O_3$ treatment for two tree grades. In seedling development, there were no significant differences for length and biomass of needle and root of two tree grades at both the control and 150 ppb of $O_3$. At 300 ppb of $O_3$ treatment, however, the length and biomass of needle and stem decreased for two tree grades but no significant differences was detected in root. The seedlings from the damaged trees were more sensitive to the $O_3$ treatment, showing higher activities of SOD, APX, and CAT and content of MDA compared to those from the healthy tree seedlings. Our results indicate that seed germination and seedling development are vulnerable to increasing $O_3$ concentrations and that attention must be paid to the individual selection of tree species for reforestation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.1
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• pp.8-13
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• 2010

Seedling establishment, overwintering ability and dry matter production of Chinese milk vetch (Astragalus sinicus L. CMV) in natural reseeding practice were compared with the annual seedling in 2006~2007 and 2007~2008. In natural reseeding, CMV seeds were distributed up to 15 cm soil depth in autumn after rice harvest and the seeds generally emerged from soil at less than 5 cm depth while they all emerged from soil surface in the annual seeding. It took 7-8 d longer in seedling establishment of the natural reseeding practice than the annual seeding. Generally, the natural reseeding practice showed higher seedling stand than the annual seeding because of high seedling survival rate. The high seedling survival rate in natural reseeded plant was attributed to the longer root length than that of the annual-seeded plant. In annual seeding, most of the seeds emerged from the soil surface and the root can not easily penetrate the soil while, in natural reseeding technology, the seeds incorporated into the soil during land preparation emerged from the soil at 0 to 5 cm depths, thereby having longer root length. The long root length contributed to greater ability to survive even under low temperature and low soil moisture conditions during winter. The dry matter production in the natural reseeding practice was also higher than the annual seeding when the temperature is low and soil moisture is not sufficient. This result indicates that natural reseeding technology is more stable and beneficial in seedling establishment and dry matter production as compared with the annual seeding especially under unfavorable environmental condition for CMV growth. This practice could be encouraged in CMV-rice cropping system in the southern parts of Korea.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.373-381
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• 2008

To select of optimum rice species and germanium (Ge) application method for production of functional rice with Ge, the growth characteristics, Ge absorption and grain quality of rice plant were investigated under different rice species (Hopyungbyeo, Junambyeo, Ilmeebyeo and Dongjinbyeo) and Ge application method (soil application and foliar spray). The rice yield by soil application was higher in the order of Hopyungbyeo $\fallingdotseq$ Junambyeo > Ilmeebyeo >> Dongjinbyeo. On the other hand, the rice yield by foliar spray was higher in the order of Junambyeo >> Ilmeebyeo > Dongjinbyeo > Hopyungbyeo. The rice yield by soil application was higher than that by foliar spray regardless of rice species. For soil application, the Ge absorption in various parts of the rice was higher in the other of rice bran > brown rice > polished rice regardless of rice species. The Ge absorption of brown rice in Hopyungbyeo, Ilmeebyeo, Dongjinbyeo and Junambyeo by soil application was 14.5, 8.0, 11.6 and $10.4\;mg\;kg^{-1}$, respectively. In leaf, stem and root, the Ge absorption by foliar spray was higher than that by soil application, whereas, in rice bran, brown rice and polished rice, the Ge absorption by soil application was higher than that by foliar spray. The optimum rice species and Ge application method were demonstrated to be Hopyungbyeo and soil application, respectively, which provided suitable conditions for production of functional rice with Ge.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.553-562
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• 2017

In these days, agricultural reservoirs are considered as a useful resource for recreational purposes, tour and cultural amenity for vicinity communities as well as irrigation water supply. However, many of the agricultural reservoirs are showing a eutrophic or hyper-eutrophic state and high level of organic contamination. In particular, about 44.7% of the aged agricultural reservoirs that constructed before 1945 exceed the water quality criteria for irrigational water use. In addition to external loading, internal nutrient loading from bottom sediment may play an important role in the nutrient budget of the aged reservoirs. The objectives of this study were to characterize variations of thermal structure of a shallow M reservoir (mean depth 1.7 m) and examine the potential of internal nutrient loading by continuous monitoring of vertical water temperature and dissolved oxygen (DO) concentration profiles in 2015 and 2016. The effect of internal loading on the total loading of the reservoir was evaluated by mass balance analysis. Results showed that a weak thermal stratification and a strong DO stratification were developed in the shallow M Reservoir. And, dynamic temporal variation in DO was observed at the bottom of the reservoir. Persistent hypoxic conditions (DO concentrations less than 2 mg/L) were established for 87 days and 98 days in 2015 and 2016, respectively, during the no-rainy summer periods. The DO concentrations intermittently increased during several events of atmospheric temperature drop and rainfall. According to the mass balance analysis, the amount of internal $PO_4-P$ loading from sediment to the overlying water were 37.9% and 39.7% of total loading during no-rainy season in 2015 and 2016, respectively on August when algae growth is enhanced with increasing water temperature. Consequently, supply of DO to the lower layer of the reservoir could be effective countermeasure to reduce nutrient release under the condition of persistent DO depletion in the bottom of the reservoir.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.4
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• pp.257-268
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• 2012

The EFDC model with find grid resolution system connecting the Gyeong-Gi bay and Han River estuary was constructed to study on spring-neap variability of net volume transport at each channel of the Han River estuary. The simulation time of numerical model is 124 days from May to August, 2009 with freshwater discharge at Han, Imjin and Yeseong River. The calibration and verification of model results was confirmed using harmonic components of water level and tidal current. The net volume transport was calculated during 30 days with normal freshwater conditions at Seokmo channel and Yeomha channel around Ganghwado. The ebbing net volume transport of 44% and 56% is drained into Gyeong-Gi bay through Yeomha and Seokmo channel, respectively. The ebbing net volume transport nearby Seodo at Yeomha channel convergence flooding net volume transport at Incheon harbor, and drain (westward direction) through channel of tidal flat between Ganghwado and Yeongjongdo to the Gyeong-Gi bay. The averaged net volume transport during 4 tidal cycles was compared to variation of spring-neap periods of the Yeomha channel. The convergence position is moved up- and down-ward according to spring-neap variability. The movement of the convergence zone is appeared because 1) increasing of discharged rate tidal flat channel between Ganghwado and Yeongjongdo at the spring period, 2) The growth of barotropic forcing with downward direction at the spring tide, and 3) The strength of the baroclinic pressure gradient is greater than spring with mixing processes.

• Journal of Life Science
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• v.26 no.1
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• pp.101-108
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• 2016

The aim of this study was to evaluate the relationships between the expression of Heat shock protein70 (HSP70), Raf-1 and Bcl-2-associated athanogene-1 (BAG1) protein in diffuse type gastric carcinoma and examine association of HSP70, Raf-1 and BAG1 expression with various clinic-pathological factors and survival. Heat shock protein70 is induced in the cells in response to various stress conditions, including carcinogens. Overexpression of heat shock protein 70 has been observed in many types of cancer. The proto-oncoprotein Raf is pivotal for mitogen-activated protein kinase (MAPK) signaling, and its aberrant activation has been implicated in multiple human cancers. Overexpression of BAG1 protein has been documented in some type of human cancer. BAG1 has been reported to interact with protein involved with a variety of signal pathway, and regulation of cell differentiation, survival and apoptosis. These interaction partners include HSP70 and Raf-1. The percentage of tumors exhibiting HSP70 positivity was significantly in cases of positive lymph node metastasis (64.9%) compared to cases without lymph node metastasis (35.1%, p=0.007). HS70 expression was correlated with pathological N-stage (p=0.006). Expression of BAG1 was detected in the majority of diffuse type gastric carcinoma tissues (71.7%), especially in younger patients (80% vs 52.6%, p=0.035). Furthermore BAG1 expression was correlated with tumor size (p=0.020). Raf-1 expression was found to be significantly associated with tumor size (p=0.005). The result indicate that HSP70 was significantly correlated the progression of diffuse type gastric cancer. Expression of BAG1 and Raf-1 may be used as diagnostic markers for gastric carcinoma.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.72-79
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• 1982

Several mutants were isolated from the parent strain of Aspergillus niger CF: the first mutant strain CF-11 was obtained by UV irradiation, and the second mutant strain CF-21 and CF-22 were from NTG (N-methyl-N'-nitroso-N-nitroso-guanidine) treatment on the CF-11. These mutants were characterized, and their enzyme and acid production on wheat bran Koji and wheat flour Koji were studied. Asp. niger CF-22 mutant appeared to be tan type which conidial heads were discolored. It's glucoamylase activity was inreased approximately two times and its ${\alpha}-amylase$ about 50 percent as compared with that of the parent strain of Asp. niger CF, when grown on wheat bran Koji under the optimal conditions. Asp. niger CF-21 mutant showed slower growth rate and poor sporulation than the wild type, although its conidial heads were not discolored. Approximately 4-fold increment in its acid production was observed as compared with the weld type. The activities of glucoamylase and ${\alpha}-amylase$ of the Asp. niger CF-22 and CF-21 mutants were higher than those of the wild type, but their protease activity was rather lower. The maximum production of glucoamylase by the Asp. niger CF-22 mutant was obtained after 2 to 3 days incubation on wheat bran at 30 to $35^{\circ}C;$ ${\alpha}-amylase$2 days incubation at 30 to $35^{\circ}C$. The maximal levels of acid production by the mutant CF-21 was appeared after 2 days incubation on wheat bran Koji, and after 3 days on wheat flour Koji at $30^{\circ}C$. Little differences in the levels of acid production were observed between on wheat bran and flour Koji.