• Title/Summary/Keyword: growing region

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Agronomical studies on the major environmental factors of rice culture in Korea (수도재배의 주요환경요인에 관한 해석적 조사연구)

  • Yung-Sup Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.3
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    • pp.49-82
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    • 1965
  • For the stable and high yields of low-land rice in Korea, the characteristics of rice plant for the vegetative and physiological responses, plant type formation, and yield components have been studied in order to obtain the fundamental data for the improvement of cultural practices, especially for the ideal fertilizer application. Furthermore the environmental conditions in Korea including temperatures, light, precipitation, and soil conditions have been compared in the broad sense with those in Japan, and the application of nitrogen, phosphorus, potassium, silicate and other micro-nutrients were described in relation to the characteristics of environmental conditions for the improvement of fertilizer application. 1. The average yield of polished-rice per 10 are in Korea is about 204 kg and this values are much less than those in Japan and Taiwan where they produce 77% to 13% more than in Korea. The rate of yield increase a year in Korea is 4.2 kg, but in Japan and Taiwan the rates of yield increase a year are 81 % and 62%, respectively. It was also found that the coefficient of variation of yield is 7.7% in Korea, 6.7% in Japan and 2.5% in Taiwan. This means that the stability of producing rice in Korea is very low when compared with those in Japan and Taiwan. 2. It was learned from the results obtained from the 'annual yield estimation experiment' that there are big differences in the respect of plant type formations between rice crops grown in Japan and Korea. The important differences found were as follows: (1) The numbers of spikelets per 3.3 square meters are 891 in Korea and 1, 007 in Japan(13% more than in Korea). (2) The numbers of tillers per 3.3 square meters at the stage of maximum tillering are 1, 150 in Korea, but in Japan they showed 19% more than in Korea. (3) The ratio of effective tillers to total tillers is 77.5% in Korea and 74.7% in Japan, which seems to be higher in Korea than in Japan. But the ratio in Korea is very low when considered the numbers of total tillers in both countries. (4) The ratio of grain to straw is 85.4% in Korea and 96.3% in Japan. 3. The average temperatures during the growing season at the area of Suwon, Kwangjoo and Taegu are almost same as those in the district of Jookokoo(Fookoo yama) in Japan, i.e., the temperatures during the rice-growing season in Korea are similar to those in the southern-warm regions of Japan. 4. Considering the minimum temperatures at the stage of limiting transplanting, 13$^{\circ}C$, the time of transplanting might be 30 to 40 days earlier than presently practicing transplanting time, which comes around June 10. 5. The temperatures during the vegetative growth in Korea were higher than those temperatures that needed in the protein synthesis which ate the main metabolism during this stage. However, the temperatures at the time of reproductive growth was lower than the temperatures that needed in the sugar assimilation which is main metabolism in this stage. In this point of view, it might be considered that the proper time of growing rice plant in Korea would be rather earlier. 6. The temperatures and the day light conditions at the time of first tillering stage of rice plant, when planted as presenting transplanting practices, are very satisfactory, but the poor day light length, high temperatures and too wet conditions in the time of last-tillering stage(mid or last July) might cause the occurrence of disease such as blast. 7. The heading stage of rice plants at each region through nations when planted as presently practicing method comes when the day light length is short. 8. It was shown that the accumulated average air-temperature at the time of maturing stage was not enough and the heading time was too late, when considered the annual deviations of mean temperatures and low minimum temperatures. 9. The nitrogen content of each plant part at the each growing stage was very high at the stage of vegetative growth when compared with the nitrogen content at the stage of reproductive growth after heading. In this respect it was believed to be important to prevent the nutrient shortages at the reproductive stages, especially after the heading. 10. The area of unsatisfactory irrigation paddy fields and natural rain-fed paddy fields are getting reduced in Korea. The correlation between the rate of reducing unsatisfactory irrigation and natural rain-fed paddy fields and the rate of yield increase were computed. The correlation coefficients(r) between the area of unsatisfactory irrigation paddy fields and yield increase were +0.525, and between the natural rain-fed paddy fields and yield increase, +0.832 and between the unsatisfactory irrigation plus natural rain-fed paddy fields and yield increase, +0.84. And there were. highly significant positive correlations between natural rain-fed paddy fields and yield increases indicating that the less the area of natural rain-fed paddy fields, the greater the yields per unit area. 11. The results obtained from the fertilizer experiments (yield performance trials) conducted in both Korea and Japan showed that the yield of non-fertilized plots per 10 are was 231 kg in Korea and 360 kg in Japan. On the basis of this it might be concluded that the fertility of soil in Korea is lower than that in Japan. Furthermore it was. also found that the yields of non-nitrogen applied plots per 10 are were 236 kg in Korea and 383 kg in Japan. This also indicates that the yields of rice in Korea are largely depending on the nitrogen content in the soil. 12. The followings were obtained when the chemical natures of soils in both Korea and Japan were compared. (1) The content of organic matter, total nitrogen, exchangeable calcium, and magnesium in Korea were no more than the half those in Japan. (2) The content of N/2 chloride and soluble silicate in low-land soil were on the average lower in Korea. (3) The exchange capacity of bases in Korea was no more than half that in Japan. 13. It was also observed by comparing the soil nature of the soil with high yielding capacity with the soil with low yielding capacity that the exchange capacity of bases, exchangeable calcium and magnesium, potassium, phosphorus, manganese, silicate and iron were low in the soil with low yielding capacity. 14. The depth of furrow slice was always deeper in the soil with high yielding capacity, and the depth of furrow slice in Korea was also shallower than that in Japan. 15. Summarizing the various conditions mentioned previously and considering the effects of silicate and trace elements such as manganese and iron besides three elements on the physiological and plant type formation of rice crops, more realistic and more ideal fertilizing practices were proposed. proposed.

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Evolutionary Explanation for Beauveria bassiana Being a Potent Biological Control Agent Against Agricultural Pests

  • Han, Jae-Gu
    • 한국균학회소식:학술대회논문집
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    • 2014.05a
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    • pp.27-28
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    • 2014
  • Beauveria bassiana (Cordycipitaceae, Hypocreales, Ascomycota) is an anamorphic fungus having a potential to be used as a biological control agent because it parasitizes a wide range of arthropod hosts including termites, aphids, beetles and many other insects. A number of bioactive secondary metabolites (SMs) have been isolated from B. bassiana and functionally verified. Among them, beauvericin and bassianolide are cyclic depsipeptides with antibiotic and insecticidal effects belonging to the enniatin family. Non-ribosomal peptide synthetases (NRPSs) play a crucial role in the synthesis of these secondary metabolites. NRPSs are modularly organized multienzyme complexes in which each module is responsible for the elongation of proteinogenic and non-protein amino acids, as well as carboxyl and hydroxyacids. A minimum of three domains are necessary for one NRPS elongation module: an adenylation (A) domain for substrate recognition and activation; a tholation (T) domain that tethers the growing peptide chain and the incoming aminoacyl unit; and a condensation (C) domain to catalyze peptide bond formation. Some of the optional domains include epimerization (E), heterocyclization (Cy) and oxidation (Ox) domains, which may modify the enzyme-bound precursors or intermediates. In the present study, we analyzed genomes of B. bassiana and its allied species in Hypocreales to verify the distribution of NRPS-encoding genes involving biosynthesis of beauvericin and bassianolide, and to unveil the evolutionary processes of the gene clusters. Initially, we retrieved completely or partially assembled genomic sequences of fungal species belonging to Hypocreales from public databases. SM biosynthesizing genes were predicted from the selected genomes using antiSMASH program. Adenylation (A) domains were extracted from the predicted NRPS, NRPS-like and NRPS-PKS hybrid genes, and used them to construct a phylogenetic tree. Based on the preliminary results of SM biosynthetic gene prediction in B. bassiana, we analyzed the conserved gene orders of beauvericin and bassianolide biosynthetic gene clusters among the hypocrealean fungi. Reciprocal best blast hit (RBH) approach was performed to identify the regions orthologous to the biosynthetic gene cluster in the selected fungal genomes. A clear recombination pattern was recognized in the inferred A-domain tree in which A-domains in the 1st and 2nd modules of beauvericin and bassianolide synthetases were grouped in CYCLO and EAS clades, respectively, suggesting that two modules of each synthetase have evolved independently. In addition, inferred topologies were congruent with the species phylogeny of Cordycipitaceae, indicating that the gene fusion event have occurred before the species divergence. Beauvericin and bassianolide synthetases turned out to possess identical domain organization as C-A-T-C-A-NM-T-T-C. We also predicted precursors of beauvericin and bassianolide synthetases based on the extracted signature residues in A-domain core motifs. The result showed that the A-domains in the 1st module of both synthetases select D-2-hydroxyisovalerate (D-Hiv), while A-domains in the 2nd modules specifically activate L-phenylalanine (Phe) in beauvericin synthetase and leucine (Leu) in bassianolide synthetase. antiSMASH ver. 2.0 predicted 15 genes in the beauvericin biosynthetic gene cluster of the B. bassiana genome dispersed across a total length of approximately 50kb. The beauvericin biosynthetic gene cluster contains beauvericin synthetase as well as kivr gene encoding NADPH-dependent ketoisovalerate reductase which is necessary to convert 2-ketoisovalarate to D-Hiv and a gene encoding a putative Gal4-like transcriptional regulator. Our syntenic comparison showed that species in Cordycipitaceae have almost conserved beauvericin biosynthetic gene cluster although the gene order and direction were sometimes variable. It is intriguing that there is no region orthologous to beauvericin synthetase gene in Cordyceps militaris genome. It is likely that beauvericin synthetase was present in common ancestor of Cordycipitaceae but selective gene loss has occurred in several species including C. militaris. Putative bassianolide biosynthetic gene cluster consisted of 16 genes including bassianolide synthetase, cytochrome P450 monooxygenase, and putative Gal4-like transcriptional regulator genes. Our synteny analysis found that only B. bassiana possessed a bassianolide synthetase gene among the studied fungi. This result is consistent with the groupings in A-domain tree in which bassianolide synthetase gene found in B. bassiana was not grouped with NRPS genes predicted in other species. We hypothesized that bassianolide biosynthesizing cluster genes in B. bassiana are possibly acquired by horizontal gene transfer (HGT) from distantly related fungi. The present study showed that B. bassiana is the only species capable of producing both beauvericin and bassianolide. This property led to B. bassiana infect multiple hosts and to be a potential biological control agent against agricultural pests.

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Development of GIS based Water Quality Simulation System for Han River and Kyeonggi Bay Area (한강과 경기만 지역 GIS 기반 통합수질모의 시스템 개발)

  • Lee, Chol-Young;Kim, Kye-Hyun
    • Journal of Korea Spatial Information System Society
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    • v.10 no.4
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    • pp.77-88
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    • 2008
  • There has been growing demands to manage the water quality of west coastal region due to the large scale urbanization along the coastal zone, the possibility of application of TMDL(Total Maximum Daily Loadings) to Han river, and the natural disaster such as oil spill incident in Taean, Chungnam. However, no system has been developed for such purposes. In this background, the demand of GIS based effective water quality management has been increased to monitor water quality environment and propose best management alternatives for Han river and Kyeonggi bay. This study mainly focused on the development of integrated water quality management system for Han river bas in and its estuary are a connected to Kyeonggi bay to support integrated water quality management and its plan. Integration was made based on GIS by spatial linking between water quality attributes and location information. A GIS DB was built to estimate the amount of generated and discharged water pollutants according to TMDL technical guide and it included input data to use two different water quality models--W ASP7 for Han river and EFDC for coastal area--to forecast water quality and to suggest BMP(Best management Practices). The results of BOD, TN, and TP from WASP7 were used as the input to run EFDC. Based on the study results, some critical areas which have relatively higher pollutant loadings were identified, and it was also identified that the locations discharging water pollutant loadings to river and seasonal factor affected water quality. And the relationship of water quality between river and its estuary area was quantitatively verified. The results showed that GIS based integrated system could be used as a tool for estimating status-quo of water quality and proposing economically effective BMPs to mitigate water pollution. Further studies need to be made for improving system's capabilities such as adding decision making function as well as cost-benefit analysis, etc. Also, the concrete methodology for water quality management using the system need to be developed.

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A study on the cooperation of Air Transport between South - North Korea (남북한 항공운송협력에 관한 연구)

  • Kim, Woong-Yi;Lee, Kang-Seok;Kim, Do-Hyun
    • The Korean Journal of Air & Space Law and Policy
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    • v.20 no.1
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    • pp.143-209
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    • 2005
  • In 1994, the North Korea indicated their intention to open up airspace. The air route passing through from Daegue FIR to Pyungyang FIR has established in 1996. The air transport cooperation between South and North Korea seemed to be reinforced at the event of President Kim, Dae-Jung's visit to North Korea by passing through a temporarily established Yellow Sea Airway in the year of 2000. The nature characteristics of air transport burdening of many circumstantial situations, however, have kept cooperation between South and North Korea from being facilitated till now. Recently as the more exchange between North and South Korea, the more frequent opportunities to discuss economic cooperation, which in sequence increased political credibility has been increased. The rail, road, and port reconnecting has realized which have been regarded impossible. Furthermore, it is expected to transport personnel and goods through South-North direct connected routes in the near future This study shows several meanings of air transport cooperation between South and North Korea. It will be far beyond simply partial air route connecting in this region, it gives great significance to realize economic cooperation and Northeast hub through air transport industry sector. This will be an exit for air transport industry have suffered limits derived from North Korea troubles and difficulties in growing as Northeast air hub. Namely, South-North air connection denote its meaning in providing opportunities Korea to be Northeast Hub and advanced country having globally competitive air transport industry To develop strategy for air transport cooperation between South and North Korea. they were developed by SWOT analysis on the basis of circumstantial analysis. These strategy need to be commanded properly to the changes of surrounded circumstances. The study result show it is desirable to apply phasal strategies by using strengths, weaknesses, threats and opportunities factors underlying analysis of inner and outer circumstances to cooperate in air transport sector.

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Study on Antioxidant Potency of Green Tea by DPPH Method (DPPH 방법을 통한 녹차의 항산화 활성에 대한 연구)

  • 오중학;김은희;김정례;문영인;강영희;강정숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.7
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    • pp.1079-1084
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    • 2004
  • The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.

A Study of Community Residents' Consciousness of Taking Herb Medicine (지역사회 주민의 한약복용에 대한 의식 조사 연구)

  • Kim Sung-Jin;Nam Chul-Hyun;Kang Young-Woo;Suh Ho-Suk;Jeon Bong-Cheon;Chang Young-Jin
    • Journal of Society of Preventive Korean Medicine
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    • v.6 no.1
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    • pp.15-35
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    • 2002
  • This study was conducted to provide basic data for policy of Oriental medicine by analyzing community resident's consciousness of taking herb medicine and its related factors. Data were collected from 1478 residents from March 2, 2001 to May 31, 2001. The results of this study are summarized as follows. 1) The rate of experience of taking herb medicine was 85.2%(88.2% of 'male'; 82.5% of 'female'). It appeared to be significantly higher in the groups of 'the married', 'housewife', and 'Buddhist'. As the age increased, so the rate of experience of taking herb medicine was significantly high. 2) In case of purpose of taking herb medicine, taking herb medicine as a restorative(66.8%) was much higher than taking it as a curative medicine. 3) 52.1% of the respondents satisfied with the effect of herb medicine. The groups of 'male', 'older age', 'residents in a big city', 'insurant in company', and 'the employed' showed significantly high rate in satisfying with herb medicine than the other groups. 4) According to the reason for preferring herb medicine, 36.7% of the respondents preferred herb medicine because the herb medicine was effective, while 27.8% preferred it because its side effect was low. 16.7% preferred it because persons around them recommended it. 5) 42.6% of the respondents did not want to take the herb medicine because the price of the herb medicine was high. Also 20.6% of the respondents did not want to take herb medicine because it is uneasy to take herb medicine. 15.8% did not want to take it because certain food should not be taken during the period of taking it. 9.4% did not want to take it because it tasted bitter. 6) In case of opinions on side effects of herb medicine, 40.8% of the respondents thinks that herb medicine is free from side effects, while 37.5% thinks that it causes side effects. There were significant difference in the opinions on side effects by sex, age, marital status, resident area, education level, occupation, and type of health insurance. 7) 60.7% of the respondents thinks the price of herb medicine is not resonable, while only 10.9% thinks it is resonable. 8) 45.2% of the respondents uses packs of decocted herbs although they think the packs of decocted herb are a little low effective because decocting herbs in home is bothersome. 45.2% uses packs of decocted herbs because they are convenient, being not related to the effect. 7.6% takes medicinal herbs after decocting them in a clay pot because they think the packs of decocted herbs have low effect. 51.9% does not know whether taking herb medicine in summer is effective or not because the effect is different according to their physical constitutions. 35.5% thinks that taking herb medicine is summer is effective because their physical stamina is weakened after sweated a lot, while 12.6% thinks that it is not effective because the effect of herb medicine disappears with sweat. 9) According to the level of satisfaction with Oriental medical care, the respondents marked $3.47{\pm}0.64$ points on the base of 5 points. It was significantly higher in the groups of 'male', 'the married, resident in a big city', 'highschool graduate', 'the unemployed', 'office clerk', 'growing up in a big city', 'insurant in region', and 'the middle class'. 10) According to the result of a regression analysis of factors influencing preference for herb medicine, the factors displayed significant difference by sex, age, education level, health status, and times of receiving Oriental medical care. As shown in the above results, the community residents satisfy with the effect of herb medicine. Therefore, the method of taking herb medicine without difficulty must be devised. The medicinal herbs in packages need to be included in health insurance coverage and resonable price of herb medicine must be set. Also, education program for community residents must be developed in order to provide right information in herb medicine. Therefore, related public authority, associations, and professionals must make efforts, forming organic cooperative system.

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A Study of Community Residents' Consciousness of Taking Herb Medicine (지역사회 주민의 한약복용에 대한 의식 조사 연구)

  • Kim Sung-Jin;Nam Chul-Hyun
    • Journal of Society of Preventive Korean Medicine
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    • v.3 no.2
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    • pp.25-53
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    • 1999
  • This study was conducted to provide basic data for policy of Oriental medicine by analyzing community residents' consciousness of taking herb medicine and its related factors. Data were collected from 1478 residents from March 2, 1999 to May 31, 1999. The results of this study are summarized as follows. 1. According to general characteristics of the subjects, 52.3% of the subjects was 'female'; 25.0% 'fifties of age'; 21.4% 'forties of age'; 20.9% 'thirties of ages'; 69.1% 'married'; 60.1% 'resident in a big city'; 12.1% 'residents in a small town or village'; 39.0% 'highschool graduate'; 35.9% 'above college graduate'; 23.4% 'housewife'; 23.4% 'professional' 34.1% 'Buddhist'; 81.1% 'middle class'. 2. The rate of experience of taking herb medicine was 85.2%(88.2% of 'male'; 82.5% of 'female'). It appeared to be significantly higher in the groups of 'the married', 'housewife', and 'Buddhist'. As the age increased, so the rate of experience of taking herb medicine was significantly high. 3. In case of purpose of taking herb medicine, taking herb medicine as a restorative(66.8%) was much higher than taking it as a curative medicine. Taking herb medicine as a curative medicine appeared to be significantly higher in the groups of 'male', 'thirties of age', 'resident in a town or village', 'above college graduate', 'professional technician', 'Christian', and 'the upper class'. 4. 52.1% of the respondents satisfied with the effect of herb medicine. The groups of 'male', 'older age', 'residents in a big city', 'insurant in company', and 'the employed' showed significantly high rate in satisfying with herb medicine than the other groups. 5. According to the reason for preferring herb medicine, 36.7% of the respondents preferred herb medicine because the herb medicine was effective, while 27.8% preferred it because its side effect was low. 16.7% preferred it. because persons around them recommended it. The preference for the herb medicine displayed significantly higher rate in the groups 'sixties of age', 'the unmarried', 'resident in a big city', 'office clerk', and 'the lower class'. 6. 42.6% of the respondents did not want to take the herb medicine because the price of the herb medicine was high. Also 20.6% of the respondents did not want to take herb medicine because it is uneasy to take herb medicine. 15.8% did not want to take it because certain foods should not be taken during the period of taking it. 9.4% did not want to take it because it tasted bitter. 7. In case of opinions on side effects of herb medicine, 40.8% of the respondents thinks that herb medicine is free from side effects, while 37.5% thinks that it causes side effects. There were significant difference in the opinions on side effects by sex, age, marital status, resident area, education level, occupation, and type of health insurance. 8. 60.7% of the respondents thinks the price of herb medicine is not resonable, while only 10.9% thinks it is resonable. 9. 14.2% of the respondents thinks health foods which contain herbs are good, while 16.8% thinks it is bad. 76.7% thinks that medicinal herbs in packages must be included in health insurance coverage, while only 3.0% thinks it needs not be included in health insurance coverage. 10. 45.2% of the respondents uses packs of decocted herbs although they think the packs of decocted herb are a little low effective because decocting herbs in home is bothersome. 45.2% uses packs of decocted herbs because they are convenient, being not related to the effect. 7.6% takes medicinal herbs after decocting them in a clay pot because they think the packs of decocted herbs have low effect. 11. According to the level of satisfaction with Oriental medical care, the respondents marked $3.47{\pm}0.64$ points on the base of 5 points. It was significantly higher in the groups of 'male', 'the married, resident in a big city', 'highschool graduate', 'the unemployed', 'office clerk', 'growing up in a big city', 'insurant in region', and 'the middle class'. 12. According to the result of a regression analysis of factors influencing preference for herb medicine, the factors displayed significant difference by sex, age, education level, health status, and times of receiving Oriental medical care. As shown in the above results, the community residents satisfy with the effect of herb medicine. Therefore, the method of taking herb medicine without difficulty must be devised. The medicinal herbs in packages need to be included in health insurance coverage and resonable price of herb medicine must be set. Also, education program for community residents must be developed in order to provide right information in herb medicine. Therefore, related public authority, associations, and professionals must make efforts, forming organic cooperative system.

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Fusaric Acid Production in Fusarium oxysporum Transformants Generated by Restriction Enzyme-Mediated Integration Procedure (Restriction Enzyme-Mediated Integration 방법으로 확보한 Fusarium oxysporum 형질전환체의 후자리산 생성능 분석)

  • Lee, Theresa;Shin, Jean Young;Son, Seung Wan;Lee, Soohyung;Ryu, Jae-Gee
    • Research in Plant Disease
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    • v.19 no.4
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    • pp.254-258
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    • 2013
  • Fusaric acid (FA) is a mycotoxin produced by Fusarium species. Its toxicity is relatively low but often associated with other mycotoxins, thus enhancing total toxicity. To date, biosynthetic genes or enzymes for FA have not been identified in F. oxysporum. In order to explore the genetic element(s) for FA biosynthesis, restriction enzyme mediated integration (REMI) procedure as an insertional mutagenesis was employed using FA producing-F. oxysporum strains. Genetic transformation of two F. oxysporum strains by REMI yielded more than 7,100 transformants with efficiency of average 3.2 transformants/${\mu}g$ DNA. To develop a screening system using phytotoxicity of FA, eleven various grains and vegetable seeds were tested for germination in cultures containing FA: Kimchi cabbage seed was selected as the most sensitive host. Screening for FA non-producer of F. oxysporum was done by growing each fungal REMI transformant in Czapek-Dox broth for 3 weeks at $25^{\circ}C$ then observing if the Kimchi cabbage seeds germinated in the culture filtrate. Of more than 5,000 REMI transformants screened, fifty-three made the seeds germinated, indicating that they produced little or fewer FA. Among them, twenty-six were analyzed for FA production by HPLC and two turned out to produce less than 1% of FA produced by a wild type strain. Sequencing of genomic DNA regions (252 bp) flanking the vector insertion site revealed an uncharacterized genomic region homologous (93%) to the F. fujikuroi genome. Further study is necessary to determine if the vector insertion sites in FA-deficient mutants are associated with FA production.

A Case Study: ICT and the Region-based Sharing Economy of a Start-up Social Enterprise (ICT 기반 지역 공유경제형 사회적 기업 사례 연구)

  • Roh, Taehyup
    • Information Systems Review
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    • v.18 no.1
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    • pp.157-175
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    • 2016
  • Under the market economy of capitalism, several limitations reveal the inequity and redistribution problem of wealth, inefficiency of over-manufacturing and over-consumption, pollution of the natural environment, and the constraint of human liberty and dignity. The new challenge of symbiotic relationships that encourage individual corporations coincides with the need to practice social responsibility and share values to overcome these limitations. Social economy and the social enterprises that simultaneously pursue the making of corporate private profits and the realization of social values have been suggested and disseminated as alternative social value creators. Furthermore, the concept of a sharing economy, which refers to the sharing of things rather than owning them, is growing traction as a new paradigm of capitalism. However, these efforts of social enterprises have fallen short against the conflicts between private profit and social values. This study deals with the case of a start-up social corporation, "Purun Bike Sharing Inc.," which is based on a regional sharing economy business model about bike rental services that use Information and Communication Technology (ICT). This corporation pursues harmonic management to achieve a balance between private profit and social value. Its corporate mission is to achieve sharing, coexistence, and contribution for public welfare. This mission is a possible idea for use in the local community network as a core key for sustainable social enterprises. The model can also be an alternative approach to overcome the structural friction in the social corporation. This study considers the case of Purun Bike Sharing as a sustainable way to practice a sharing economy business model based on a regional cooperation network, which can be combined with social value, and to apply ICT to a sharing economy system. It also examines the definition and current state of social enterprises and the sharing economy, and the cases of the sharing economy business model for the review of prior research.

A Study on Difficulty Factors of Youth Startups for Activating Local Startups (지역창업 활성화를 위한 청년창업 애로 요인에 관한 연구)

  • Ahn, Tae-Uk;Kang, Tae-Won
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.2
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    • pp.67-80
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    • 2020
  • This study has been conducted at a time when Korean government continues to extend support for youth startups as part of its policy to create jobs and the focus moves from career and employment to youth startups with a growing interest in the field of youth startups. Against this background, this study aims to identify difficulty factors of youth startups in areas besides the Seoul Metropolitan Area, seek ways to overcome difficulty factors, and propose policy implications. To this end, this study set five criteria and 25 sub-criteria to evaluate the difficulties of youth startups by reviewing previous studies and conducting literature review, and performing brainstorming method. The empirical analysis of the evaluation criteria was performed, using the analytic hierarchy process (AHP) method, on youths aged 19 to 39 in Gunsan area. The analysis results showed that the largest difficulty factors facing local youths include business model establishment, business administration and management, and startup funding in the criteria. As for sub-criteria, the largest difficulty factors are market information acquisition, technology commercialization, project feasibility, technology development, and new market pioneering in descending order. Local youths have much difficulty about the process of turning a business item into a product and commercializing it. According to a comparative analysis by gender, men were a relatively high difficulty in commercializing business models than women. men were a relatively high difficulty in commercializing business models than women. On the other hand, women were higher than men in all factors (management management, entrepreneurship, improvement of entrepreneurship system, and improvement of entrepreneurship awareness) except for factors affecting business model. In addition, the factors of entrepreneurship were found to be relatively different among young people (college students, prospective entrepreneurs, entrepreneurs). In conclusion, it was suggested that in order to revitalize youth entrepreneurship in the region, it is necessary to actively resolve the difficulties of business model commercialization rather than entrepreneurship funds. In addition, it is necessary to strategically support customized entrepreneurship support and situational administrative services because gender and hierarchical difficulties are different than general solutions. This study presented practical priorities and derivation methods for the entrepreneurship difficulties faced by local youth, and suggested measures and improvements for vitalizing local youth entrepreneurship in the future.