• Korean Journal of Ecology and Environment
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• v.49 no.3
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• pp.228-235
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• 2016

Aquatic ecosystems are receiving various harmful effects due to anthropogenic chemical pollutions. To protect wildlife, risk assessments of the chemicals are conducted using reference indexes of toxicity estimated by species-level laboratory tests and/or micro-/mesocosm community-level studies. However, the existing micro-/mesocosm communities are structurally too complicated, and it is also difficult to compare the experimental results directly with those from species-level tests. Here, we developed a procedure of a simple bi-trophic microcosm experiment which contains the common species (a green algae, Pseudokirchneriella subcapitata and a cladoceran, Daphnia magna) for testing chemical toxicities. For the proper operation of bitrophic microcosm experiment, the minimum required concentration of primary producer (P. subcapitata) is $5{\times}10^5cells\;mL^{-1}$. The microcosm system showed higher stability when the initially introduced D. magna population was composed of neonates (<24-h old) than adults and those mixture. This simple microcosm system would be an applicable tool to estimate the disturbing impacts of pollutants on plant-herbivore interactions, and linking the species- and population-/community level risk assessments in the future studies.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.2
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• pp.110-120
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• 2004

This research sought to analyze the food waste collection and transportation system in Korea's related public resource-making facilities, address related problems, and suggest a reasonable alternative measure. For the food waste sorting-out and discharging methods, apartments and similar housings use containers, and individual-style housings use 'quantity-proportional' bags. The sorting and discharging methods should be improved to boost the reuse of resource-made output. The analysis of collection and transportation costs by local governments indicates that they range from 30,000 won to 150,000 won per ton, varying greatly by characteristics of local governments, thus suggesting a need to establish costs calculation criteria to justify the costs. Charges imposed to each household were not greatly problematic in the case of quantity-proportional bags; however, in the case of apartments and similar housings, charges varied greatly, suggesting a need to impose differentiated charges calculated on the basis of collection and transportation costs according to regions. Many places used household-garbage collection vehicles to collect food waste, raising the possibility of causing complaints on leaching water and bad odors. Thus, exclusive food waste collection vehicles should be gradually introduced. Also, in certain places, vehicles should travel more than 20km to collect food waste, and in such cases, a cargo transferring system should be introduced to boost efficiency in carriage.

• Journal of the Korean Geotechnical Society
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• v.34 no.7
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• pp.17-27
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• 2018

Sinkholes have occurred in various places around the world and concerns about public safety have been raised in recent years. Particularly, a ground subsidence may occur due to a variety of conditions when developing underground spaces. Ground subsidence refers to the sinking of the Earth's surface caused by the loss of the soil constituting ground due to a certain artificial cause in the ground. Ground subsidence is induced by artificial causes such as the leakage of water supply/sewage pipes and groundwater disturbance, and it is different from a sinkhole, where the sinking of the Earth's surface is induced by the cavity formed due to the melting of limestone in the ground with limestone bedrock. In recent underground development in the urban areas of Korea, damages to surrounding buildings have frequently led to many difficulties with civil complaints and compensation issues, and the collapse of some buildings has resulted in the loss of lives and property. Accordingly, the central government has legislated the Special Act on Underground Safety Management, which will take effect from January 1, 2018. This law specifies an underground safety management system for securing underground safety, under which underground safety impact assessment is performed for projects involving underground excavation work that exceeds a certain size, and safety inspection is regularly performed for underground facilities and the surrounding ground. In this study, the contents of the special act on underground safety management are reviewed, and the direction of development of underground safety policy for preparing preemptive underground safety management preparation and response system is suggested.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.1
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• pp.82-92
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• 2013

This paper presents a landscape design proposal for the Kyeongsang National University Hospital in Changwon, Kyeongsangnam-do. The site is located at 555 Samjeongja-dong, Seongsan-gu, Changwon, Kyeongsangnam-do, and its area is approximately $79,743.1m^2$. The goal of the design was to create a landscape that helps the patients' recovery and public well-being as well as respects the surrounding environment. In order to achieve this goal, three design subjects were considered: maximizing the healing functions of the landscape, promoting ecologically regenerative landscape, and increasing the aesthetic value of the landscape based on the local context. For the healing aspect, first, therapeutic plants were carefully selected and various healing programs were introduced to the open space area such as the sensory garden, meditative space, the medicinal herb garden, outdoor acupressure treatment facilities, remedial playground etc. In addition, as the importance of patient's privacy is emphasized in research, the space and circulation patterns were divided according to the characteristics of the users. For ecological consideration, the design proposed to preserve and extend the existing ridgeline with pine forest, and recover the natural water system and recycle the water for the landscape management. For the aesthetic experience of the people, in contrast to the surrounding evergreen forest, diverse deciduous and flowering plants were introduced to arouse a sense of the season, and fruit bearing trees for wildlife to create a specific mood of being in nature so that people can listen to the songs of the birds and watch squirrels play etc. In addition, all the spaces and facilities were designed and placed according to universal design principles so that there would be no barrier for the patients to use them. Also, a sustainable management scheme was suggested to maintain the landscape in ecological and economical ways.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.277-283
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• 2001

The emergence of extended spectrum beta-lactamase(ESBL) producing bacteria is causing very serious problems in Korea. Although there have been many reports about these bacteria isolated from patients and clinical specimens, there is no report of ESBL-producing organisms isolated from natural evironment in Korea. This is the first study on the ESBL producing bacteria out of the medical system in Korea. Twenty-six ESBL producing bacteria were isolated only from sewerage plant drain water at Kwang-an beach among the sampling collected sites including snakehead fish plants in Myungi, Aquaculture Engineering Lab. in Pukyong National University and two public-bathrooms in Pusan, Korea. ESBL producing bacteria were identified by double-disk synergy test, conjugation, isoelectric focusing values and PCR. The species of ESBL producing bacteria were Enterobacter cloacae(4 strains), E. sakazakii(8 strains), Klebsiella pneumoniae subsp. pneumoniae(8 strains) and K. pneumoniae subsp. ozaenae(6 strains). TEM and SHV specific PCR products were detected from all the ESBL strains produced TEM+SHV products on the PCR plates. The pI values of ESBL produced by Klebsiella pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, Enterobacter cloacae, and E. sakazakii were 5.9, 5.9+5.4; 5.9, $5.9+5.4;{\ge}8.5$, 8.0+5.4, and 8.0+5.4, respectively on the IEF. Seven strains of the isolates were transfered their genes to E. coli RG488 $Rif^r$ by conjugation.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.93-101
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• 2024

Background: As pollutants caused by non-point sources flow into rivers, river water quality monitoring for fecal pollution is becoming increasingly important. Objectives: This study was conducted to investigate the distribution of microbial communities in the Yeongsangang River water system and sewage treatment plants in Gwangju and to evaluate their antibiotic resistance. Methods: In the experiment, samples were distributed to five selective media at each point and then cultured for 18 to 24 hours. When bacteria were observed, they were sub-cultured by size and shape and identified using MALDI-TOF MS equipment. When identification was completed, 17 types of antibiotic susceptibility tests were performed using VITEK II equipment, focusing on gram-negative dominant species among the identified strains. Results: During the study period, a total of 266 strains were isolated from 39 samples. Gram-positive bacteria were 37 strains in four genera, or 13.9% of the total, and Gram-negative bacteria were 229 strains in 23 genera, or 86.1% of the total. Antibiotic susceptibility testing of 23 strains, the major dominant species, showed that one strain (4.3%) was resistant to only one antibiotic, and two strains (8.7%) were 100% susceptible to the 17 antibiotics tested. The other 20 strains (87.0%) were multidrug resistant bacteria resistant to two or more antibiotics. There were various types of multidrug resistance. Among them, penicillin and cephalosporin series showed the highest resistance. Conclusions: Based on the results of this study, it was found that the bacterial community structure changed according to regional and environmental factors, and it was judged that continuous research such as genetic analysis of antibiotic-resistant bacteria present in natural rivers is necessary.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.234-243
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• 2007

Algal growth potential (AGP) test was performed to evaluate the water quality and changes in phytoplankton communities before and after a heavy rain event at six sampling sites in Cheonggye Stream (St. 1 and 2), Jungnang Stream (St. 3 and 4), and Lower part of Han River System (St. 5 and 6) after rehabilitation of Cheonggye Stream, October 2005. To test AGP on each sampling site, cyanobacterium Microcystis aeruginosa was applied as a standard alga. Total nitrogen (TN) showed high values at Jungnang Stream, while St. 4 recorded highest values in this study. However, TN values of Cheonggye Stream and Lower Part of Han River showed similar levels. Total phosphate (TP) also showed high values at Jungnang Stream, while St. 4 recorded highest. However, TP in Cheonggye Stream were extremely low levels. Although chlorophyll-${\alpha}$ (chi-${\alpha}$) contents before the rain event were similar through the sampling sites, chl-${\alpha}$ after the rain increased dramatically at Jungnang Stream and Lower part of Ban River. In particular, after the rain, TP was the highest at St. 4, where Cyclotella sp. dominated the phytoplankton community. When compared with control, AGP values before the rain were comparatively low in all sites, while those after the rain highly increased with the dose-dependently of field water added, due perhaps to the increased nutrients by rainfall. Similar results were observed in Cheonggye Stream. Therefore, for the aesthetic fostering for the citizens, although Cheonggye Stream was Presently being sustained by treated water supply, they have a potential of outbreak of phytoplankton by the increased nutrients supply when a heavy rain comes.

• Journal of agricultural medicine and community health
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• v.43 no.4
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• pp.258-269
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• 2018

Objectives: There was an outbreak of foodborne and waterborne disease among high school students at Okcheon in June, 2018. First attack occurred June $5^{th}$ but seven days later it was notified. The purpose of this investigation was to evaluate the pathogen of outbreak and cause of delayed notification. Methods: First, we did a questionnaire survey for 61 cases and 122 controls to find what symptoms they had and whether they ate foods or drank water from June $2^{nd}$ to June $12^{th}$. Second, we investigated the environment of cafeteria and drinking water. Third, we examined specimen of cases and environment to identify bacteria or virus. Results: Attack rate of this outbreak was 7.8%. Drinking water was strongly suspected as a source of infection in questionnaire survey but we could not find the exact time of exposure. Norovirus was identified in specimen of cases (2 students), drinking water (at main building and dormitory) and cafeteria (knife, dishtowel, hand of chef) Conclusions: We decided norovirus as the pathogen of this outbreak based on the clinical features of cases with diarrhea vomiting, abdominal pain and recovery within 2 or 3 days after onset, outbreak due to drinking water and microbiologic examination, And the cause of delayed notification might be the non-existence of the nurse teacher at that time and the lack of understanding of teachers on immediate notification under the outbreak. To prevent the delayed notification, notification system about outbreak of foodborne and waterborne disease in school is needed to be improved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.167-171
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• 2004

The growth of soybean sprout was greatly influenced by watering systems： Fixed watering system (water tub was loaded at ceiling upper of culture box and water was showered by bottom holes) was estimated the better than that of reciprocating watering and tub immersing watering because it could cool down the temperature in culture box and wash the organic substances on the body of sprout. The fixed watering system showed good body color and preventing effect of partial rotting of sprout because it could discharge $\textrm{CO}_2$ gas effectively in culture box and keep the concentration below 5%. The concentration of gases at the bottom (about 30 cm height from basal plate) of culture box in fourth or fifth days was L6% for $\textrm{CO}_2$ and 13-16% for $\textrm{O}_2$, respectively. The optimum gas concentration in culture box was considered to be over 10% for $\textrm{O}_2$ and below 5% for $\textrm{CO}_2$.

• KSBB Journal
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• v.24 no.3
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• pp.227-238
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• 2009

In the recent years, some organic toxic chemicals were used for obtaining high-yield productivity in agriculture. The undegraded pesticides may remain in the agricultural foods through atmosphere, water, and soil and cause public health problems to environmental resources and human beings even at very low concentrations. Small amounts of pesticides can affect a central nervous system, resulting in immunogenic diseases, infertility problems, respiratory diseases and born marrow diseases, which can lead even to death. Monitoring of the environmental pesticide is one of the important issues for the human well-being. Several kinds of biosensors have been successfully applied to the detection of agrichemical toxicity. Also, few platforms for biocide detection have been definitely developed for the degradation and reaction of pesticides. Biochip and electrochemistry experiments involve immobilizing a receptor molecule on a solid substrate surface, and monitoring its interaction with an analyze in a sample solution. Furthermore, nanotechnology can be applied to make high-throughput analyses that are smaller, faster and sensitive than conventional assays. Some nanomaterials or nanofabricated surfaces can be coupled to biomolecules and used in antibody-based assays and enzymatic methods for pesticide residues. The operation procedure has become more convenient as it does not require labeling procedure. In this paper, we review the recent advances in agrichemical defection research and also describe the label-free biosensor for pesticides using various useful detection methods.