• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.247-252
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• 2012

This study examined the control effects of amino acid biochemical agent extracted from chicken feathers on Meloidogyne incognita for the purpose of developing an environmentally friendly nematicidal agent that can replace chemical control of root-knot nematodes (RKN). We investigated the lethal effects of J2 juveniles for 19 types of commercial amino acids. As a result, five kinds of amino acids (L-asparagine, L-aspartic acid, L-methionine, L-tyrosine, L-cysteine) showed mortality rate of more than 50% at a concentration of 50 mM. L-asparagine showed the highest mortality rate at 94%. We also investigated the lethal effect of J2 juveniles and suppressive effects of egg hatching by feather amino acids (FAA) biochemical agent. It showed that the mortality rate of J2 juveniles was more than 80% and suppression rate of egg hatching was 74% at 1/50 concentrations of FAA. As a result of conducting a tomato pot culture experiment for 60 days after treating 1/50 concentrations of FAA biochemical agent in rhizosphere soil, it showed that the control effects were 63% of juveniles density in the soil, 59% of egg mass and 61% of root gall index, respectively. Based on the above results, it is considered that the FAA biochemical agent extracted from chicken feathers can be used as an environmentally friendly nematicidal agent of RKN.

• Ecology and Resilient Infrastructure
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• v.4 no.3
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• pp.130-141
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• 2017

We evaluated the field application feasibility that biologically derived substances (Naphthoquinone derivate: NQ 2-0) can be used for the eco-friendly mitigation of natural harmful cyanobacterial blooms in freshwater. We conducted a 30 ton scale mesocosm experiment to investigate the effects of NQ 2-0 on biotic and abiotic factors in water collected from Gi-heung reservoir. In the mesocosm experiments, the abundance of Microcystis sp. was continuously increased in the control. However, the Microcystis sp. cell density was sharply decreased on the $10^{th}$ day. In the treatment, NQ 2-0 showed the strong and selective algicidal activity toward the target cyanobacteria (Microcystis sp.). Accordingly, the algicidal activity of NQ 2-0 compound increased gradually until $10^{th}$, $15^{th}$ days and algal biomass was decreased to 99.4 and 100 %, respectively. NQ 2-0 compound was not only selective algicidal activity but also the growth of other phytoplankton and increased the Shannon-Wiener diversity index of phytoplankton. In the mesocosm experiments, the dynamics of biotic (bacteria, heterotrophic nanoflagellate, ciliates, zooplankton) and abiotic (water temperature, dissolved oxygen, pH, conductivity, nutrients) factors remained unaffected. These results suggest that NQ 2-0 could be a selective and ecologically safe algicide to mitigate harmful cyanobacterial blooms. In addition, it is believed that NQ 2-0 will play a major role in forming a healthy aquatic ecosystem by facilitating habitat and food supply of aquatic organisms.

• Ecology and Resilient Infrastructure
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• v.8 no.3
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• pp.135-142
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• 2021

Biopolymers have been known as eco-friendly soil strengthening materials and studied to apply levees. However, the effect of biopolymer on vegetation is not fully understood. In this study, we analyzed the root growth of Camelina sativa L. (Camelina) when the xanthan gum was amended to soil in Aluminum (Al) stress conditions. Amendment of 0.05% xanthan gum increased root growth of Camelina under Al stress conditions. Under the Al stress condition, expression of aluminum activate malate transporter 1 (ALMT1) gene of Camelina root was induced but showed a lower level of expression in xanthan gum amended soil than non-amended soil. Additionally, the binding capacity of xanthan gum with Al ions in the solution was confirmed. Using morin staining and ICP-OES analysis, the Al content of the roots in the xanthan gum soil was lower than in the non-xanthan gum soil. These results suggest that xanthan gum amended soils may reduce the detrimental effects of Al on the roots and positively affect the growth of plants. Therefore, xanthan gum is not only an eco-friendly construction material but also can protect the roots in the disadvantageous environment of the plant.

• Korean Journal of Ecology and Environment
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• v.45 no.4
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• pp.453-458
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• 2012

The golden apple snail, Pomacea canaliculata, is a freshwater snail native to tropical and subtropical South America. The species was introduced into Korea as a human food source in 1983 and was first applied as a weed control agent for the paddy fields in 1992. As the snail is well known as an environmentally friendly biological control agent for weeds, the area of cultivation in which the golden apple snail is used for biological control has been enlarged substantially each year. Currently, the species is observed in open water courses. It is possible that the snail may overwinter in these open water courses and may become a serious pest, as is already the case in many Asian countries. In this study, we determined the status of the overwintering golden apple snail based on a literature survey and investigated the potential distribution area of the snail, as a result from global warming in Korea. The potential distribution area of the overwintering golden apple snail would be enlarged under the influence of global warming; ranging from 45.5% of South Korea's land area in the 2020s to 88.4% in the 2080s.

• Research in Plant Disease
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• v.9 no.2
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• pp.57-63
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• 2003

Clubroot disease of curcifer crops caused by Plasmodiophora brassicae had been first reported in 1928 in Korea, and maintained mild occurrence until 1980s. Since 1990s the disease has become severe in alpine areas of Kyonggi and Kangwon, gradually spread to plain fields throughout the country, and remains as the great-est limiting factor for its production. Researches on the disease has begun in late 1990s after experiencing severe epidemics. Survey of occurrence and etiological studies have been carried out, particularly, on the pathogen physiology, race identification, quantification of soil pathogen population, and host spectrum of the pathogen. Ecology of gall formation and its decay, yield loss assessment associated with time of infection, and relationships between crop rotation and the disease incidence was also studied during late 1990s. In studies of its control, more than 200 crucifer cultivars were evaluated for their resistance to the disease. Lime applica-tion to field soil was also attempted to reduce the disease incidence. Resistant radish and welsh onion were recommended as rotation crops with crucifers after 3-year field experiments. However, so for, most studies on clubroot disease in Korea have been focused on chemical control. Two fungicides, fluazinam and flusulfamide, were selected and extensively studied on their application technologies and combination effects with lime application or other soil treatment. To develop environmentally-friendly control methods, solar-disinfection of soil, phosphoric acid as a nontoxic compound, and root-parasiting endophytes as biocontrol agents were examined for their effects on the disease in fields. In the future, more researches are needed to be done on development of resistant varieties effective to several races of the pathogen, establishment of economically-sound crop rotation system, and improvement of soil-disinfection technique applicable to Korean field condi-tion, and development of methodology of pretreatment of fungicides onto seeds and seedbeds.

• Hwankyungkyoyuk
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• v.21 no.1
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• pp.16-30
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• 2008

This study was aimed at finding what effects pro-con discussion classes have on students' environmental decisions and set a series of research questions as follows. First, in a small group discussion, how a student's environmental decision is affected by opinions of other students in the same group. Second, what would be the relations between a students' personal factors including gender, environmental knowledge, attitude, and behavior and their decisions. A decisional experiment was applied to 185 students consisting of 2 girl classes and 4 boy classes of K highschool located in Kongju City, Chungnam. These students were taking 'Ecology and Environment' as one of the few general selective subjects once a week. Decision issue introduced to the experiment was regarding of constructing a wind power station on Baekdu Mountains which is protected by the law. This issue can be characterized as not conflict between conservation and development but conflict between two different types of environment friendly approaches that make students experience more difficult while making a decision. The results of this study an be summarized as follows. First, after taking the class introducing environmental issues and having a debate other students on the issue both within a small group or all classmates together, just less then 30% of the students changed their selections. Second, students were found to be affected by other students' opinion while making his or her own decision. Third, no relationship was found to be statistically considerable between students decisions and their personal factors except of their courses, liberal or science.

• International Journal of Human Ecology
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• v.16 no.2
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• pp.1-9
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• 2015

This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

• Ecology and Resilient Infrastructure
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• v.2 no.2
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• pp.147-153
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• 2015

Various adverse effects can occur due to direct exposure from toxic substances when toxic materials are used to restore river ecosystems. Thus, this study performed analysis on the development of toxicity in terms of survival and abnormality rates using embryos of Bombina orientalis living in Korea to analyze the toxicity of materials used in the river projects. The results showed that the toxicity in cement (C group) was the strongest whereas the toxicity in plant-based polyurethane (P1 group) was the weakest. Survival rates of B. orientalis embryos were 100%, 94 - 95%, 66 - 89% and 0% in control, P1, polyurethane (P2) and C groups, respectively. Abnormalities of embryos were 10.5%, 5.3 - 10.5%, 26.3 - 27.8% and 35.7% in control, P1, P2 and C groups, respectively. Furthermore, we verified that having a sufficient curing time reduced toxic substances that were extracted. The above result suggest that cement and polyurethane hamper the early development of amphibians. In conclusion, it is highly important to review biological safety with respect to the selection of materials used to restore rivers. This study shows the importance of the selection of eco-friendly materials and processes.

• Ecology and Resilient Infrastructure
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• v.10 no.2
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• pp.40-49
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• 2023

To reduce the damage of extreme flooding caused by climate change and to create flood mitigation sections in a nature-friendly riparian area, it is necessary to restore the floodplain area by referring to the past floodplain section of the current inland waterfront area before the levee was built. This study proposed a method of selecting a location for floodplain restoration using old maps of the Geum River study section and analyzed the effect of flood level reduction through unsteady flow numerical simulations using the floodplain as a flood mitigation space. As a result of analyzing changes in the river areas using old maps, the river section was estimated to gradually reduce by 27.8% (1,059,380 m²) in 2020 compared to 1919, and it was found to have an effective storage capacity of 2,200,868 m³ when restored to offline storage. The flood level and discharge control effects analyzed based on HEC-RAS unsteady flow simulation were 16 cm and 219.01 m³/s, respectively, in the downstream cross-section. In the numerical simulation in this paper, the flood mitigation space was applied as an offline reservoir. The effect of reducing the flood level may differ if levee retreat/relocation is applied.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.2 s.115
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• pp.113-127
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• 2006

As the local self-government are stabilized and the environmental value is becoming more important among local residents, the occurrence of the anti-movements against waste treatment facilities is getting more frequent. Opposing to build the reuse facilities of wastes takes place because of concerning of health and hygiene, as well as matters of unclear policy making process. However, these facilities must be built in somewhere for the convenience and profit of the public. The NIMBY phenomenon against reuse facilities of wastes could be a burden for the city operation system, and it could worsen citizens' quality of life in the long run. In these lights, reuse and recycling facilities of wastes in East region are necessary facilities improving citizens' quality of life and enhancing the growth of cities in the region. However, there have been concerning of deforestation during the construction process of the facilities. The landscape design presented here for these facilities considers the features of the environmental ecosystem and tries to establish a plan to preserve the natural environment of the City of Ichon. This paper presents methods minimizing adverse effects of the facilities on the existing environments and promoting the city image with integrating culture, tourism, landscape and environment of the city. The landscape design makes efforts to harmonize natural environments in the site, human activities and culture. Well-being park was aimed to lead healthy and energetic outdoor activities of local residents. Ecological park was aimed to enhance the ecological functions of the forests and restore the valley ecology. Culture park was aimed to capture the city identity by creating a place that contains all the variety of meanings of the City of Ichon.