• 인간식물환경학회지
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• 제24권6호
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• pp.551-561
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• 2021

Background and objective: Vietnam is prioritizing agricultural production for food export capacity in all national policies. As a result, for three decades, its agriculture has been making quite many remarkable achievements. Methods: The most successful one is that the nation has become one of the world's leading rice exporters and ensures its national food security. Through these endeavors, the Mekong River Delta (MRD), in particular, has emerged as a key region in ensuring national food security and rice export. Results: The new era can now see Vietnamese agriculture turning to place special emphasis on commodity quality and the improvement of the living environment. This is evidenced, for example, by the phenomenon that the MRD, as a rice basket of the whole country, is making moves back to nature-based agriculture with attempts to restore the natural ecology, including preserving and restoring local traditional rice seeds, adopting natural farming practices and minimizing the use of chemical fertilizers and pesticides. Conclusion: The case studies of nature-based farming practices in the MRD indicate that, while the national agriculture is generally developing large-scale production, the small-scale farming in the region, integrated with tourist and educational activities on-site, is meeting the demands of a highly potential domestic niche market. Moreover, this model appears to be a sustainable farming approach that defines itself as a working green livelihood for the region.

• 한국환경농학회지
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• 제1권2호
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• pp.83-88
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• 1982

광주근교 경작지 토양 53점의 유기염소계 살충제 8종의 잔류분을 분석(分析)하여 다음과 같은 결과(結果)를 얻었다. 1) Dieldrin을 제외한 7종(種)의 유기염소계 살충제(有機鹽素系 殺蟲劑)의 잔류분(殘留分)이 60% 이상(以上)의 시료(試料)에서 검출(檢出)되었다. 특히 ${\alpha}-BHC$는 거의 모든 시료(試料)에서 검출(檢出)되었으며 p,p'-DDT의 잔류수준이 가장 높았다. 2) 논 토양보다는 밭 토양에서 높은 오염률(汚染率)과 높은 잔류수준(殘留水準)을 보였다. 3) 경지정리답과 미정리답의 유기염소계 살충제의 잔류수준은 차이가 거의 없었다.

• Toxicological Research
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• 제21권4호
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• pp.297-301
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• 2005

Farmers are generally expressed to pesticides through mixing loding, application activity and harvesting of crop after application of pesticides. The present work investigated the exposure and risk of furathiocarb to workers when harvesting of cucumber was carried out in green house after application of furathiocarb EC. Glove was used for the hand exposure assessment, socks for foot and dermal patches for the other parts of body. Personal air monitor equipped with a XAD-2 resin was used for the respiratory exposure assessment. During the harvest of cucumber in green house, the initial rate of potential dermal exposure (Day 1) for methidathion was 1.3 mg/hr. The major exposure parts were hand $(78\~83\%),\;thigh\;(5\~7\%)$ and arms $(6\~9\%)$ during 3 days' harvest. No exposure was detected from the respiratory monitoring. For risk assessment, the potential dermal exposure (PDE), the absorbable quantity of exposure (AQE) and the margin of safety (MOS) and margin of exposure (MOE) were calculated. In risk assessment of harvester exposure for 7days, all MOS was > 1 and MOE was > 100 indicating that possibility of risk was little.

• 한국환경농학회지
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• 제28권3호
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• pp.289-294
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• 2009

사과 재배에 피해를 주고 있는 사과 겹무늬썩음병, 탄저병, 라이족토니아병을 복합적으로 방제하기 위한 기초연구로서 각 병원균에 대하여 우수한 길항력을 동시에 가지는 길항미생물을 선발하고 Streptomyces sp. S-1110으로 동정하였다. 분리된 길항미생물은 배양상등액으로 길항물질을 분비하였으며 우수한 열안정성과 pH 안정성을 가지는 특성이 있었으며 각 병원균에 대한 감수성이 조금씩 달라서 2 종 이상의 길항물질이 동시에 생산되어 길항작용을 하는 것으로 추정되었다. 또한 분리균이 생산하는 길항물질을 사과 과실에 직접접종된 사과 겹무늬썩음병과 탄저병의 방제를 위해 실험한 결과 높은 방제력을 보였다. 따라서 분리된 길항미생물은 사과 과수원 및 저장소에서 동시에 수종의 질병방제에 쓰일 수 있는 천연 복합방제제의 개발을 위한 기초 균주로의 가치가 높은 것으로 판단된다.

• Water Engineering Research
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• 제7권1호
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• pp.1-8
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• 2006

Recently, the population growth and agricultural development are rapidly undergoing in the South-West Texas. The junction of three river basins such as Lavaca river basin, Colorado-Lavaca Coastal basin and Lavaca-Guadalupe Coastal basin, are interesting for non-point and point source pollutant modeling: Especially, the 2 basins are an intensively agricultural region (Colorado-Lavaca Coastal/Lavaca-Guadalupe Coastal basins) and several cities are rapidly extended. In case of the Lavaca river basin, there are many range land. Several habitat types wide-spread over three relatively larger basins and five wastewater discharge regions are located in there. There are different hazardous substances which have been released. Total nutrient loads are composed of land surface load and river load as Non-point source and discharge from wastewater facilities as point source. In 3 basins region, where point and non-point sources of poll Jtion may be a big concern, because increasing fertilizers and pesticides use and population cause. This project objective seeks to how to assess and control the accumulation of non-point and point source and discuss the main impacts of agriculture and environmental concern as non-point source with water quality related to pesticides, fertilizer, and nutrients and as point source with wasterwater discharge from cities. The GIS technique has been developed to aid in the point and non-point source analysis of impacts to natural resource within watershed. This project shows the losses in $kg/km^2/year$ of BOD (Biological Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) in the runoff from the surface of 3 basins. In the next paper, sediment contamination will show how to evaluate in Estuarine habitats of these downstream.

• 한국산업보건학회지
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• 제22권4호
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• pp.309-315
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• 2012

Objectives: Animal husbandry workers could be exposed to various work hazards including toxic gases, chemicals such as pesticides or organic dust. Immunological evaluation focusing on respiratory allergic hypersensitivity occurrence was under-taken for swine farm workers as a part of the study on immunologic status of dairy barn, swine confinement, and poultry farm workers. Materials and Methods: Peripheral bloods were collected from 25 workers at the year of 2001 and 12 workers at the year of 2012 from swine farms located at Gyeonggi province, Korea. Seven adults not involved with animal husbandry were recruited at the year of 2001 from the same residential area as the swine farm workers'. Level of plasma IgE and 20 respiratory allergen-specific IgE were evaluated using commercially available ELISA kit. Results: Plasma IgE level was approximately five-fold higher in the swine farm workers regardless of the sampling year than the control subjects. Plant allergens from outdoor environments such as golden rod, pigweed, Russian thistle, or ragweed were the major allergens with positive reaction(allergen specific IgE${\geq}$0.7 IU/mL) for the swine farm workers at 2001 year. Meanwhile, house dust mite(Dermatophagoides farinae, D. pteronyssinus) and cockroach, typical indoor allergens in Korea, were the major respiratory allergens for the swine farm workers at 2012 year. Conclusions: Overall, even though our results are primitive, the results suggest that immunological function of swine farm workers could be modulated toward type-2 reactivity.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.351-357
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• 2005

Endosulfan is one of the organochlorine pesticides, which are well-known endocrine disruptors (EDs), and it acts as an estrogen agonist. Estrogen is a group of hormones that play an important role in mammary gland function and are implicated in mammary carcinogenesis. In the present study, we studied the effects of endosulfan on nodule like alveolar lesion (NLAL) formation in mouse mammary gland development using a mouse mammary gland organ culture (MMOC) system. Although endosulfan-treated mammary glands did not form NLALs, more alveolar buds were formed in this group than in the negative control (vehicle-treated) group. In addition, telomerase reverse transcriptase (TERT) mRNA expression levels were increased in endosulfan-treated mammary glands in a dose-dependent manner. Telomerase can be activated by estrogen, therefore, we examined the effects of endosulfan on telomerase activity, and found that the telomerase activity in estrogen receptor-positive MCF-7 cells was up-regulated by endosulfan treatment. Moreover, this activation was accompanied by the up­regulation of the TERT mRNA expression. Also, transient expression assays using CAT reporter plasm ids containing various fragments of the TERT promoter showed that this imperfect palindromic estrogen-responsive element is almost certainly responsible for the transcriptional activation by endosulfan. These results may help elucidate the endocrine disrupting mechanism of endosulfan.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1905-1911
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• 2020

Homoserine dehydrogenase (HSD) catalyzes the reversible conversion of ʟ-aspartate-4-semialdehyde to ʟ-homoserine in the aspartate pathway for the biosynthesis of lysine, methionine, threonine, and isoleucine. HSD has attracted great attention for medical and industrial purposes due to its recognized application in the development of pesticides and is being utilized in the large scale production of ʟ-lysine. In this study, HSD from Bacillus subtilis (BsHSD) was overexpressed in Escherichia coli and purified to homogeneity for biochemical characterization. We examined the enzymatic activity of BsHSD for ʟ-homoserine oxidation and found that BsHSD exclusively prefers NADP+ to NAD+ and that its activity was maximal at pH 9.0 and in the presence of 0.4 M NaCl. By kinetic analysis, Km values for ʟ-homoserine and NADP+ were found to be 35.08 ± 2.91 mM and 0.39 ± 0.05 mM, respectively, and the Vmax values were 2.72 ± 0.06 μmol/min-1 mg-1 and 2.79 ± 0.11 μmol/min-1 mg-1, respectively. The apparent molecular mass determined with size-exclusion chromatography indicated that BsHSD forms a tetramer, in contrast to the previously reported dimeric HSDs from other organisms. This novel oligomeric assembly can be attributed to the additional C-terminal ACT domain of BsHSD. Thermal denaturation monitoring by circular dichroism spectroscopy was used to determine its melting temperature, which was 54.8℃. The molecular and biochemical features of BsHSD revealed in this study may lay the foundation for future studies on amino acid metabolism and its application for industrial and medical purposes.

• 한국유기농업학회:학술대회논문집
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• 한국유기농업학회 2001년도 심포지엄
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• pp.248-265
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• 2001

Recently, agriculture in Korea is seriously depressed by economic globalization and trade liberalization because of low competitive power. Organic farming, which is favorable for small scale agriculture, is expected to be one of alternatives to boost agricultural activities in Korea. Organic agriculture requires systemic developments of new technologies considering the complex biological interaction within the system in connection with high quality and safety standard. The National Institute of Agricultural Science & Technology(NIAST) has been worked on the series of organic farming technologies, including bio-pesticides, pheromone, natural enemies as well as the testings of materials used in organic farming. NIAST will concentrate on the technological development for compromising to the conflict between commodity-oriented and ecological harmony. Research on systemic land and water use, management of plant nutrition, pest and disease control, post-harvest would also be important targets. Integrated efforts among researchers, professors, administrators, farmers, private sectors, and extension workers are substantial for fast technology development and its dissemination. Development and use of these technologies will homely enlighten the Korean organic farming although it may require quite a time and endeavor.

• 농약과학회지
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• 제18권1호
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• pp.48-51
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• 2014

Since the year of 2006 when the extended revision of the Codex Classification of Foods and Animal Feeds was undertaken, considerable progresses have been made in revising the Classification. This paper aimed to summarize the present status on revision of the Codex Classification of Foods and Animal Feeds, focusing remarkable achievements such as 1) the draft revision of the Codex Classification for the fruit commodity group and 2) the draft Principles and Guidance on the Selection of Representative Commodities for the Extrapolation of Maximum Residue Limits for Pesticides to Commodity Groups, adopted by the Codex Alimentarius Commission in 2012. Additionally, it included information on lists of crop group or subgroup which are holding at Step 7 and were adopted at Step 5, and further have not been yet discussed by the Codex Committee on Pesticide Residues. These information will be very helpful for a pesticide regulatory regime.