• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.177-185
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• 2014

Aspiring to the new raw materials of insecticides is one of the plant extracts. The material structure of a variety of plant extracts have because the material to the defense of the plant itself, the case of insecticides, using plant extracts, safe, has low toxicity and has the advantage of highly distinctive and fall. Coltsfoot (Tussilago farfara L.) is belonging to the family Compositae, and distributed in all parts of China as medicinal plants and indigenous plants used. Coltsfoot is known that it is effect to respiratory disease and has an antiviral effect. However, the reported insecticidal activity of coltsfoot could be not found. Fortunately, I found insecticidal activities when I was screening the bioassay against several insects with a lot of plant extracts. Using the ethanol extract of the Tussilago farfara, there were insecticidal activities against Culex pipiens pallens and Tetranychus urticae. There were several fractions in ethanol extract of coltsfoot by using various organic solvents. Hexane fraction showed a higher insecticidal activity than any other fraction. It is confirmed that hexane fraction contained pyrethrin by using HPLC analysis. So, it might be suggested that extract of coltsfoot has an insecticidal activity and its effect due to a ingredient of pyrethrin.

• Korean Journal of Organic Agriculture
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• v.10 no.1
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• pp.1-18
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• 2002

The aim of this study was to introduce the history and development of German organic farming(Bio-dynamic Agriculture and organic agriculture) which has a worldwide reputation and initiative in organic agriculture. And also the organization of organic producer's or farmer's group such as AGOL, POB, OSL, ALOG & Schweisfurth Stiftung and its regional distribution, the basic standard of organic farming and certification system for organic food, an actual cultivated area for organic forming and organic livestock were also shortly reported. The government subsidizing programmes and Agenda 2000, the extension services for organic farming by government and private level, the research activities of organic agriculture by governmental research body(FAL) and universities, the education system for organic agriculture in the German universities(University of Bonn, Gesamthochschule Kassel, University of Hohenheim, University of Gie$\beta$en and etc) were also explained. In the conclusion it was suggested several issues what should be considered to facilitate an organic farming in Korea in the view of organic production, marketing, distributing, extension and organic processing.

• 한국약용작물학회:학술대회논문집
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• 2007.11a
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• pp.292.1-292.1
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• 2007

• Korean Journal of Organic Agriculture
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• v.4 no.1
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• pp.59-73
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• 1995

Some devices of sustaining the small scale farming in the changing social and economic conditions in which comparative disadvantages are evidently to be experienced in the near future, are becoming a central proposition in the Korean agriculture. In this connection, development of integrated activities in farming among individual farmers within a region may be an important device of overcoming prevailing limits of resource possession and use of individual farmers. These inter-farm or inter-group cooperation and integration can be promoted through establishing efficient cooperative system within a farming district. This study was undertaken to find facts pertaining to situations leading to successful performence of cooperative systems in group farming. In this study, The case in Cheunee Myun, Yungi-Gun, Chungchungnam-Do in which farming is specialized in production of so called "organic farming products" and farmers are integrated for increasing their productivity.ductivity.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.189-195
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• 1997

Twenty six per cent of Canada's core biotech companies are Ag-biotechnology, compared with five per cent in the United States. Activities include the use of microorganisms, plant cells to create commercially viable products, and transformation of plants to improve specific qualities. Goals ate to increase the world's food supply, enable crops and animals to resist pests and diseases, increase the nutritional content of food, and improve production efficiency. I believe that there are business opportunities in the agriculture sector for Canada and other countries such as Korea to collaborate. These are research to research : institute to institute: business to business, and combinations of these areas. However, for these opportunities to become a reality we need to increase our awareness of each other's activities and needs. My presentation today was not designed with specifics, but to encourage some strategic thinking by both countries on how we can do business together in agriculture and biotechnology.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1741-1746
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• 2006

3D-QSARs on the neuroblocking activities by 1-(6-chloro-3-pyridylmethyl)-2-nitroiminoimidazolidine analogues as agonist at the nicotinic acetylcholine receptor (nAChR) were studied quantitatively using CoMFA and CoMSIA methodologies. The statistical results of CoMFA (A5: $r^2\;_{cv.}\;=\;0.707\;&\;r^2\;_{ncv.}$= 0.986) and CoMSIA model (A3: $r^2\;_{cv.}$ = 0.715 & $r^2\;_{ncv.}$ = 0.961) showed the best predictability and fitness for neuroblocking activity based on the cross-validated value and non-cross validated value. The steric and H-bond acceptor nature of a compound were essential for high activity. The study on 3D-QSARs between substrate molecules and their neuroblocking activities appears to be an useful approach for designing better neuroblocking drug development.

• Preventive Nutrition and Food Science
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• v.19 no.1
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• pp.27-33
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• 2014

Hydrolysates of Trianthema portulacastrum in acidified methanol were evaluated for their total phenolic (TP) constituents and respective antioxidant activities using in vitro assays (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, percent inhibition of linoleic acid peroxidation, and ferric reducing power). The observed results indicate that root, shoot, and leaf fractions of T. portulacastrum contain 50.75~98.09 mg gallic acid equivalents/g dry weight of TP. In addition, these fractions have substantial reducing potentials (0.10~0.59), abilities to inhibit peroxidation (43.26~89.98%), and DPPH radical scavenging capabilities ($6.98{\sim}311.61{\mu}g/mL$ $IC_{50}$). The experimental data not only reveal T. portulacastrum as potential source of valuable antioxidants, but also indicate that acidified methanol may be an ideal choice for the enhanced recovery of phenolic compounds with retained biological potential for the food and pharmaceutical industry.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.52-57
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• 2007

Quantitative structure-activity relationships (QSARs) on the inhibition activities by oleanolic acid analogues (1-19) as a potent inhibitor against protein tyrosine phosphatase-1B were studied quantitatively using 2D-QSAR and HQSAR methodologies. The inhibition activity was dependent on the variations of $R_{4-}$substituent, and as shown in 2D-QSAR model ($r^2=0.928$), it has a tendency to increase as the negative Randic Indice (RI) goes up. The size of the molecular fragments used in HQSAR varied from five to eight. The fragment distinctions had the best statistic value, whose predictability is $q^2=0.785$ and correlation coefficient is $r^2=0.970$, on condition of connections. From the atomic contribution maps, the factor that contributes to the inhibition activities is the $C_{15}{\sim}C_{17}$ bond in the D ring. From the analysis result of these two the models, the structural distinctions and descriptors that contribute to the inhibition activities were obtained.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1758-1763
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• 2000

The effect of tu-chung (Eucommia ulmoides, Oliver) leaf meal on reducing lipid accumulation in chickens fed 1% cholesterol containing diet was studied. Forty male White Leghorn chickens aged 56 days were weighed and divided into four groups of ten chickens, and fed diets with or without 1% dietary cholesterol which were supplemented with 0 and 5% tu-chung. Tu-chung supplementation to the diet without cholesterol increased acetyl-CoA carboxylase (p<0.01) but decreased 3-hydroxy-3-methylglutaryl-CoA reductase activities (p<0.01) with no effect on fatty acid synthetase activities. However, its supplementation to the diet with cholesterol had no effect on these three enzyme activities as compared with the cholesterol containing diet without tu-chung. Tu-chung supplementation to the diet without cholesterol increased hepatic triglyceride (p<0.01), whereas its supplementation to the diet with cholesterol decreased it (p<0.01). Tu-chung supplementation to the diet with cholesterol decreased plasma cholesterol ester, free cholesterol, phospholipids (p<0.05) and triglyceride (p<0.01) as compared with the cholesterol containing diet without tu-chung. Supplementation of tu-chung to the diet without cholesterol decreased plasma free cholesterol (p<0.05). It is concluded that tu-chung leaf meal reduced an increase in lipid accumulation in chickens stimulated by 1% cholesterol feeding.

• Korean Journal of Organic Agriculture
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• v.30 no.4
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• pp.485-497
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• 2022

Agricultural environmental policies to reduce negative externalities and expand positive externalities became common around the world. However, literature regarding the efficient and effective implementation of agricultural environmental policies, such as optional direct payment, is limited. This study, thus, analyzes the relative importance for target selecting-criteria in order to enhance the cost-effectiveness of the Agricultural Environment Conservation Program in Korea. In this context, we conducted survey to 15 experts who are related in agricultural environment policies and analyzed survey results based on ANP method which can consider correlation between selecting criteria. The results show that, in the case field, "soil", "water", and "ecology" field have relative high importance than the other fields. Also, the relative importance for 'improving rural landscape', 'giving nutrient input moderately', and 'conserving agricultural heritage' activities is higher than the other activities. Furthermore, the relative importance among fields and activities of ANP is different from those of AHP. This result implies that it is necessary to consider the correlation between selecting criteria in order to design effectively. Finally, we suggest that in order to enhance the effectiveness of the program, it would be appropriate to assign differential points according to the importance of each activity when identifying appropriate farms.