• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.129-133
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• 1982

This study was conducted to find out the resistance of rice varieties to ozone gas. Thirty eight rice varieties were exposed to 0.3 ppm $O_3$ gas for 3 hours. Damage symptom, percentage of destroyed leaf and chlorophyll contents were observed after $O_3$ fumigation. The results obtained are as follows. 1) Typical symptom of $O_3$ damage appeared to greyish subtle spots in Japonica type and redish brown subtle spots in Indica-Japonica hybrid type within rice leaf vein. 2) Resistant varieties to $O_3$ gas were Palgwangbyeo, Seokwangbyeo and Milyang 30, while sensitive ones were Gwanakbyeo, Jinjubyeo and Hankangchalbyeo. 3) Chlorophyll damage of rice leaves were higher in Nongbaeck, Dobongbyeo, Palgeum, Jinjubyeo than in Milyang 21, Podgwangbyeo, Josaeongtongil, Honamjosaeng, Hwanggeumbyeo. 4) The amount of chlorophyll damage showed highly significant positive correlation with that of leaf destruction.

• Korean Journal of Environmental Agriculture
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• v.15 no.3
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• pp.335-340
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• 1996

A green house experiment was conducted to investigate the growth of Chinese cabbage, radish and soybean and change in the chemical properties of the soil after the 10mm application of the simulated acid rain(SAR) of pH 2.7 in the form of sprinkle and mist. It was applied 30 times for Chinese cabbage and radish and 62 times for soybean at the two-day intervals. The results obtained are summarized as follows: 1. Visual damages caused by SAR were dark-brown or red brown leaf spots in Chinese cabbage, and dark-brown and wrinkled leaf margins in radish and soybean. 2. The degree of visual damages became severer as the number of SAR applications increased and it was severer with mist than with sprinkle of SAR. 3. Chlorophyll content was reduced by SAR, but it was not affected by the form of SAR application(sprinkle or mist) in all crops, although it was slightly lower with mist than with sprinkle of SAR. 4. Fresh weight of Chinese cabbage heads and radish roots and grain yield of soybean were reduced by SAR, and were not affected by the form of SAR application. 5. Contents of K, Ca, and Mg in leaves were reduced, while S content increased by SAR in all crops. The forms of SAR application did not affect contents of mineral nutrients in all crops. 6. SAR decreased soil pH and the contents Ca, Mg, and K of soil, while increased $SO_4$ content. However, the contents of soil organic matter, N, and P were not affected by SAR. Forms of SAR application did not affect soil chemical properties either.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.293-298
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• 2017

The purpose of this study was to analyze the risk factors of depression in elementary school students in Korea. The subjects of the study were 23,291 elementary school students (12,016 male, 11,275 female) aged 9 to 12 years. Dependent variable was defined as experience of depression. Explanatory variables were included as sex, residential areas, social discrimination experience, experience of school violence for the past year, experience of Korean language education, experience of using multicultural family support center, reading to Korean, speaking to Korean, and writing to Korean, listening to Korean. In the RBF neural network analysis, experience of Korean education, experience of school violence, experience of Korean social discrimination, level of Korean reading were significantly associated with depression in elementary school students. In order to prevent depression in multicultural children, priority attention and counseling are needed for the group whose level of Korean reading is low.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.1
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• pp.118-122
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• 1997

We experienced a case of 51-year-old female patient who showed symptoms of persecutory delusion, auditory hallucination and hallucinatory behavior, severe insomnia, psychomotor retardation and social withdrawal, along with some clinical signs of the deficiency of various hormones those gradually progressed after massive postpartum vaginal bleeding 13 years ago. She was admitted to a psychiatric ward under the impression of psychotic depression. However careful history taking and evaluation of clinical feature gave rise to the possibility of underlying medical condition. Laboratory work-up revealed panhypopituitarism, hypoglycemia and hyponatremia. After replacement of thyroid hormone and cortisol for 1 week, her clinical symptoms including psychiatric symptoms were improved. Taken together, these findings were compatible with the diagnosis of Sheehan's syndrome. On reporting this case, we would like to emphasize again the importance of differential diagnosis of medical problems causing psychiatric symptoms those are easily neglected in the clinical approach toward psychiatric patients.

• Korean Journal of Environmental Agriculture
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• v.11 no.2
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• pp.133-139
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• 1992

Removal of heavy metals by water hyacinth, Eichhornia crassipes Solms-Laub, was examined with two heavy metals Cd, Cu under laboratory conditions. Cd in culture solution was reducd to 0.116, 0.873, 2.015, 3.755 and 4,747 mg/L from 1, 2, 3, 4 and 5 mg/L for 24 hrs, after cultivating of water hyacinth respectively And, Cu was reduced to 0.086, 0.600, 2.174, 3.473, and 4.365 mg/L from 1, 2, 3, 4, and 5 mg/L for 24 hrs, after the cultivation, respectively. Cu was removed faster than Cd nd airating cultivation was effected higher than fixing cultivation. Removal effect of heavy metals by water hyacinth was higher in low a heavy metal cocentration than in high concentration

• Anxiety and mood
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• v.13 no.1
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• pp.25-31
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• 2017

Objective : The purpose of this study was to evaluate the factors associated with the experience of bullying victimization in school among elementary school students in the Jeju area. Methods : A total of 662 students were recruited from elementary schools for a school-based cross-sectional survey (age range : 11-12 years) in the Jeju area. This study used a self-reported questionnaire concerning the experience of being victimized by bullying, the Korean form of the Children's Depression Inventory (CDI) to assess depressive symptoms, and questions on sociodemographic characteristics, including school- and family-related factors. Results : The prevalence of bullying victimization in school among elementary school students was 10.0% (n=66). The factors associated with bullying victimization were lower socioeconomic status, lower than average academic achievement, more depressive symptoms, and family problems. Conclusion : This study not only indicates that bullying at school is a significant public health issue among elementary school students, but also confirms that children with family problems commonly exhibit bullying behaviors, which highlights the importance of considering family-related environmental factors when managing bullying victimization.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.87-90
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• 2013

The average annual and winter ambient air temperatures in Korea have risen by $0.7^{\circ}C$ and $1.4^{\circ}C$, respectively, during the last 30 years. Due to climate change, the occurrence of abnormal weather conditions has become more frequent, causing damage to vegetable crops grown in Korea. Hot pepper, chinese cabbage and radish, the three most popular vegetables in Korea, are produced more in the field than in the greenhouse. It has been a trend that the time for field transplanting of seedlings is getting earlier and earlier as the spring temperatures keep rising. Seedlings transplanted too early in the spring take a longer time to resume the normal growth, because they are exposed to suboptimal temperature conditions. This experiment was carried out to figure out the change of cellular tissue of chinese cabbage under the condition of low temperature to provide the information regarding the coming climatic change, on the performance of 'Chunkwang' chinese cabbage during the spring growing season. In our study, plant height, number of leaf, chlorophyll and leaf area was lower at the open field cultivation than heating house treatment after transplanting 50 days. Especially in fresh weight, compared with heating treatment, open field and not heated treatment were notably low with the 1/3 level. Of damage symptoms due to low temperature cabbage leaves about 10 sheets when $-3.0^{\circ}C$ conditions in chinese cabbage was a little bit of water soaking symptoms on the leaves. $-7.4^{\circ}C$ under increasingly severe water soaking symptoms of leaf turns yellow was dry. Microscopy results showed symptoms of $-3.0^{\circ}C$ when the mesophyll cell of palisade tissue and spongy tissue collapse, $-7.4^{\circ}C$ palisade tissue and spongy tissue was completely collapsed. The result of this study suggests that the growers should be cautioned not to transplant their chinese cabbage seedlings too early into the field, and should be re-transplanting or transplanting other plants if chinese cabbage are exposed to suboptimal temperature conditions ($-3.0^{\circ}C$ or $-7.4^{\circ}C$).

• Research in Plant Disease
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• v.25 no.4
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• pp.237-242
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• 2019

Severe damage on a greenhouse grown lettuce (Lactuca sativa L.) associated with Paratylenchus projectus is described for the first time. There were no marketable lettuce in entire greenhouse after three months of planting. Lettuce roots system appeared corky and most of feeder rootlets disappeared. Population densities of P. projectus were ranged from 320-11,600 nematodes per 100 ㎤ of soil. In an inoculation test in a greenhouse, P. projectus is proved as a causal agent of lettuce damage.

• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.282-288
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• 1995

To investigate the alterations in the ultrastructure of leaves by acid rain, 10mm of SAR(Simulated Acid Rain, pH 2.0, 2.7, 3.0, 6.0) was applied to three crops(red-pepper, perilla, eggplant) at a two-day interval. The symptoms of leaf damage by SAR were observed by naked eyes and SEM(Scanning Electron Microscope), and the peroxidase activity in the leaves was measured. The results are summarized as follows : The severity of SAR damages to the crops observed by naked eye were in the decreasing order of red-pepper, perilla, and eggplant. The Symptoms were characterized by brown or white spots on the leaf surface. In the SAR treatment of pH 3.0, trichomes of all crops except for eggplant were damaged. By the SAR treatment of pH 2.7, stomata were damaged in all crops. With one time treatment of SAR, the peroxidase activity of perilla was rapidly increased.

• Korean Journal of Environmental Agriculture
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• v.2 no.2
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• pp.103-107
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• 1983

The effect of photochemical oxidants on rice plants was measured by growing the rice plants Nihonbare in pot in charcoal-manganese oxide filtered atmosphere and non-filtered air. Visible injury on the leaf blades of rice plants were observed in plants grown under the unfiltered air chamber, but plants under filtered air chamber were free from any injury. Fresh weight of stem and root at maximum tillering stage in unfiltered chamber were 16.8 and 46.4% less than filtered air chamber, respectively. Grain yield in unfiltered air chamber was also reduced by 14.7% compared to that of filtered air chamber. And the reduced yield paralleled increase in concentration of oxidants in the atmosphere at the experimental site. ABA content in rice plants cultivated in unfiltered air chamber was higher than in filtered air chamber, but the root activity of rice plants in unfiltered air chamber was remarkably decreased.