• Journal of Life Science
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• v.27 no.2
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• pp.247-266
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• 2017

Cordyceps is a traditional Chinese medicinal herb well-known in China, Korea and Japan since B.C. 2,000. The original entomopathogenic fungus, Cordyceps sinensis belonging to the genus Cordyceps could not be found inside Korean peninsula due to the absence of the host insect for the corresponding entomogenous fungus. The development of artificial production methods of Korean type Cordyceps using the silkworm Bombyx mori as in vivo culture medium for the the entomopathogenic fungus Paecilomyces tenuipes is the first, and wonderful occasion in the research history of insect industry of this global world. The aim of this article is to review the historical research background, mass-production methods, and pharmacological effects of the silkworm-dongchunghacho (Paecilomyces tenuipes) which is a newly developed Korean medicinal insect-borne mushroom, and another non-insect-borne medicinal mushroom (Cordyceps militaris and Cordyceps pruinosa). Their biological actions include anti-tumor, immunostimulating, anti-fatigue, anti-stress, anti-oxidant, anti-aging, anti-diabetic, anti-inflammatory, anti-thrombosis, hypolipidaemic and insecticidal effects. The bioactive principles are protein-bound polysaccharides (hexose, hexosamin), cordycepin, D-manitol, acidic polysaccharide etc. Protein-bound polysaccharides and n-butanol fractions were demonstrated to show a significant anti-tumor activities but did not show a cytotoxicities. D-mannitol exhibited a significant prolongation of the life span in tumor bearing mice. Ergosterol did not show an efficient anti-tumor activity, but showed a significant phagocytosis enhancing activity. Anti-tumor activity of silkworm-dongchunghacho might be attributed to immuno-stimulating activities rather than cytotoxic effects [164]. Also this review comprises the breeding of Dongchunghacho varieties, optimization of culture conditions, improvement of learning and memory by Dongchunghacho, application of them as foods and chemical constituents.

• Korean Journal of Organic Agriculture
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• v.13 no.3
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• pp.315-332
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• 2005

This study was conducted to assess the nutritional value and the safety of the fermented food wastes (FFW) made by adding lactobacillus spp. and bacillus spp. at the ratio of 3:7, respectively to food wastes collected everywhere, and also to determine effects on the performances, carcass characteristics and economical profitability when FFW was fed to pigs. For swine trial, FFW was formulate to pellet by utilizing different feed ingredients, and its formulated FFW pellet was used in this feeding trial. Treatments were consisted of different ratios (T1: $100+0\%$, T2: $75+25\%$, T3: $50+50\%$, T4: $25+75\%$, T5: $0+100\%$) of FFW pellet to commercial diet. A total of 20 male pigs were allotted to treatments of five groups of four pigs per pen. Experimental period lasted for 4 months. The nutritional composition of FFW was 56.7, 19.5 and $19.5\%$ for moisture, crude protein and ether extract, respectively. Salt content was $0.39\%$. Noxious microorganisms such as salmonella and E. coli were not detected in FFW, and contents of heavy metal and aflatoxin B1 were lower than the standard. Nutritional values of FFW pellet satisfied over $100\%$ of requirements presented in official Korean feeding standard for swine. Feeding trial for pigs showed that feed intakes were significantly (P<0.05) decreased with increasing levels of FFW pellet. T2 treatment was ideal ratio under the consideration of economical value of feeds and body weight gain of pigs. For carcass characteristics, dressing rate ($\%$) was highest in T3, and carcass grades for T2, T3 and T4 treatments were estimated as 'A'. Feed cost for FFW per kg was ${\won}167.95$, which implies $52\%$ of commercial feed cost (${\won}350/kg$). Thus, this result implied the decreased feed cost in the swine farm. Conclusively, the utilization of food wastes as feed source may lead to the reduced environmental pollution and the practice of organic livestock farming. However, our results showed that excessive amount of fermented food wastes supplementation to pigs might give rise to their reduced palatability and delayed growth.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1079-1088
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• 2003

This study was conducted to test the efficacy of the automatic liquid feeder(designated as NLRI) developed by National Livestock Research Institute, Korea for 7-day old early-weaning piglets. The other automatic liquid feeder imported from USA(designated as IALF) was used for a comparative purpose. A total of sixty piglets of 7 days of age were allotted to three treatments. The control group of 20 piglets was raised by their own sows until 21 days of age, while others were shifted to automatic liquid feeders of either NLRI or IALF on 7 days of age and reared during 14 days post-weaning. After then, all the piglets were fed nutritionally identical mash diets until 70 days of age. Compared with control group, body weight of piglets reared on automatic liquid feeders were lighter(P〈0.05) at 21 days of age [5.55kg (control) vs 4.97 (NLRI) and 4.98kg (IALF)], while heavier(P〈0.05) at 70 days of age(24.82kg vs 30.17 and 29.42kg). The results indicated that pigs reared on liquid feeding showed higher(P〈0.05) average daily gain than control pigs during the whole experimental period [346.7g (control) vs 425.8 (NLRI) and 416.1g (IALF)], while no difference was found in feed/gain (1.67 vs 1.78 and 1.84). There was no difference in growth performance and incidence of diarrhea between two automatic liquid feeders, NLRI and IALF. Compared with control group, intestinal villi tended to be shorter in liquid feeding group during the first week, but were recovered within two weeks. The results suggest that the automatic liquid feeder newly developed by National Livestock Research Institute, Korea can be successfully used for rearing young piglets weaned at very early age.

• Korean Journal of Poultry Science
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• v.20 no.1
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• pp.1-9
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• 1993

This study carried out to build up new synthetic egg production lines which had sex-linked gene for feather color sexing and also superior combining ability for producing the best commercial chicks. The closed flock breeding method was utilized to improve the general performances in the first experiment and combining ability for heterosis was tested for new synthetic line in the second experimental year. In order to test for the egg production ability in cross breeds synthetic lines, the crossing of B$\times$4 B$\times$C, two imported strains and two domestic strains as controls were compared for the general performances. There was on difference in mortality, body weight to 56 weeks of age. Sexual maturity was delayed about 10 days by comparing with other reports, except 153 days of the Manina White, but no difference among mating systems in this experiment. The hen housed egg production in B$\times$A, B$\times$C was 186.3, 191.3 respectively and it was better than the other controls, except ISA imported lines. The hen-day egg production of B$\times$A, B$\times$C was better than other controls, with 75.7%, 76.8% respectively. In the average egg weight, the B$\times$C cross breed was highest with 64.5g. As the sex of hatching chicks was identified by difference of feather color, the genetic composition of synthetic lines must be homogenized. The feather color of female chicks was brown and that of male was silver (99%), In conclusion, the egg production ability of B$\times$A, B$\times$C cross breeds was superior to the imported and domestic lines. Therefore, it suggest that the synthetic lines with sex-linked gene might be utilized for improving egg production performances.

• Korean Journal of Social Welfare
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• v.56 no.3
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• pp.159-181
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• 2004

This study examines the realities and causes of youth and new college graduate unemployment, and seeks some assignments for mitigating youth and new college graduate unemployment. An analysis of the realities and causes of youth and new college graduate unemployment is summarized as follows. First, youth unemployment rate, which rapidly increased after the IMF economic crisis, slowly decreased after 2000, but was still somewhat higher in 2002 than that before the IMF. Second, new college graduate unemployment rate, which rapidly increased after the IMF economic crisis, slowly decreased after 2000 and became a similar level to that before the IMF economic crisis, but the number of the unemployed new college graduates highly increased after the IMF. Third, an analysis of the causes of youth unemployment shows that economic growth and the employment elasticity of economic growth negatively affect the unemployment rate, and the rate of entrance into colleges positively affects the unemployment rate. Fourth, an analysis of the causes of new college graduate unemployment demonstrates that economic growth and the employment elasticity of economic growth negatively affect the unemployment rate, and the increase rate of new college graduates, the college graduate/youth population ratio, and the time trend positively affect the unemployment rate. These results suggest several implications for mitigating the unemployment rate of the youth and new college graduates. First, in order to increase labor demand, emphasis must be placed on preparing economic conditions which can raise economic growth rate and on fostering industries and occupations which have high employment elasticity. Second, in the aspect of labor supply, it is necessary to adjust the number of new college graduates corresponding to labor demands in industries. Third, in order to redress the mismatch between the demand and the supply of the youth labor market, attention should be paid to remedying educational systems such as the activation of vocational education and training in middle and high schools and the reformation of college education to match the education and training provided in colleges and the skills requirements of the world of work, and preparing a unified program to support the youth unemployed systematically and synthetically.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.73-78
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• 1994

This experiment was carried out to investigate the major characteristics associated with the flavor rate and their changes according to days after silking of super sweet corn(Cocktail 86) for vegetable and waxy corn(Chalok 1). Ear elongation finished around 22∼24 days after silking. In kernel development, elongation was much more prominant in super sweet corn than that in waxy corn but thickness was vice versa. Pericarp thickness and kernel hardness of super sweet corn were slightly increased but those of waxy corn were increased rapidly as the ears matured. Moisture and sucrose content of super sweet corn remained high but the waxy corn was not. The reducing sugars(glucose, fructose) were relatively high at the early maturity stage but they were decreased as the ears matured and negatively correlated with sucrose and flavor rate. Soluble solids (Brix %) were positively correlated with sucrose and total sugar(sucrose+ glucose+fructose) content in waxy corn but not in super sweet corn and was considered as inappropriate criate criterion to envaluate the sugar content and flavor rate. Pericarp thickness and sucrose content were positively correlated with the flavor rate in both hybrids but total sugar content, and kernel hardness were positively correlated with flavor rate in super sweet corn and waxy corn respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.409-412
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• 2002

This research was conducted to obtain the fundamental data on salt injury and different responses among cultivars in winter barley (Hordeum vulgare L.). Salts did not affect yield components including number of panicles, stem length, grain number per ear and grain yield while reduced stem dry weight and thousand seed weight significantly with increasing concentrations of salt from 60 to 180 mM. NaCl had less injury effect on barley straw dry weight and thousand seed weight than did $MgSO_4$. Chlorophyll content and relative turgidity in flag leaf were reduced when treated with both salts, while free proline in the salt-treated leaf was increased. Content of proline in salt-treated barley was about 10 folds compared to the control. Based on yield components and physiological traits of flag leaf, the tolerance to salt injury was the greatest in Baegdong, followed by Dongbori#1, Mogpo#55, and Gangbori. The results suggested that salt- stressed barley at reproductive stage had higher free proline content, and that special management in this stage must be considered because salt stress at heading stage affect flag leaf growth as well as yield components Harmfully.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.4
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• pp.375-383
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• 2009

This study was carried out to develop transgenic rice cultivars with the CAX1 (accession no. U57411) gene. We successfully selected the transgenic rice plants over-expressing the Arabidopsis H+/$Ca^{2+}$ antiporter CAX1 (accession no. U57411) gene in T6 generation. The brown rice of the CAX1 expressing rice contained 13.4~68.0 % more calcium $(Ca^{2+})$ than that of the wild type and 5 lines were selected based on the phenotypes compared to the control cultivar at the GMO field. The CAX1 expressing transgenic rice plants were similar in phenotype to the wild type during the whole growth period. Also these selected 4 lines appeared to be resistant to blast, cold and water solution compared with the wild type. Difference in 1,000 grain weight of brown rice was observed among each line but grain shape did not show any morphological alternations. These results suggest the enhanced Ca-substrate specificity of CAX1 exchanger in donor plant. Therefore, intact CAX1 exchanger can be functionally useful for $Ca^{2+}$ nutrient enrichment of rice with reduced accumulation of undesirable cation.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.24-29
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• 2013

In the present study, the effects of prebiotics and prebiotics+probiotics on intestinal microflora and fermentation products were evaluated in a pig in vitro fermentation model. The substrates used in this study were iso-malto oligosaccharide (IMO), partially digested chicory-inulin (CI), raffinose (RA), and cyclodextrin (CD) as prebiotics and Lactobacillus reiteri as probiotics. For a pig in vitro fermentation, the experimental diet for growing pigs was predigested using digestive enzymes secreted by small intestine and this hydrolyzed diet was mixed with a buffer solution containing 5% fresh swine feces. The mixture was then incubated with either prebiotics or prebiotics+probiotics for 24 h. Samples were taken at 24 h, and viable counts of microflora, gas, pH, volatile organic compounds (VOCs) and short-chain fatty acid (SCFA) were analyzed. The viable count of Enterobacteriaceae was significantly decreased (p<0.001) in all treatments containing prebiotics and prebiotics+probiotics when compared to the control. However, the number of lactic acid bacteria increased in the prebiotics and prebiotics+probiotics treatment. The pH values in the fermentation fluid decreased in all treatments when compared to the control, and their effects were greater in the prebiotics+probiotics group than prebiotics group. Fermentation with prebiotics resulted in a reduction in malodorous compounds such as ammonia, hydrogen sulfide and skatole when compared to the prebiotics+probiotics group. Short-chain fatty acid production was also higher for treatment with prebiotics+probiotics than treatment with prebiotics. In conclusion, the results of this study demonstrated that fermentation with prebiotics was effective in reducing the formation of malodorous compounds and prebiotics+probiotics was effective in increasing lactic acid bacteria and SCFA and reducing the pH. Moreover, further studies will be needed to determine whether the results observed in the in vitro model would occur in pigs that ingest these prebiotics or probiotics.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.318-329
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• 2014

In order to gain insight into the physiological responses of plants to high temperature stress, the effects of temperature on Chinese cabbage (Brassica campestris subsp. napus var. pekinensis cv. Detong) were investigated through analyses of photosynthesis and chlorophyll fluorescence under 3 different temperatures in the temperature gradient tunnel. Growth (leaf length and number of leaves) during the rosette stage was greater at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures than at ambient temperature. Photosynthetic $CO_2$ fixation rates of Chinese cabbage grown under the different temperatures did not differ significantly. However, dark respiration rate was significantly higher in the cabbage that developed under ambient temperature relative to elevated temperature. Furthermore, elevated growth temperature increased transpiration rate and stomatal conductance resulting in an overall decrease of water use efficiency. The chlorophyll a fluorescence transient was also considerably affected by high temperature stress; the fluorescence yield $F_J$, $F_I$, and $F_P$ decreased considerably at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures, with induction of $F_K$ and decrease of $F_V/F_O$. The values of RC/CS, ABS/CS, TRo/CS, and ETo/CS decreased considerably, while DIo/CS increased with increased growth temperature. The symptoms of soft-rot disease were observed in the inner part of the cabbage heads after 7, 9, and/or 10 weeks of cultivation at ambient $+4^{\circ}C$ and ambient $+7^{\circ}C$ temperatures, but not in the cabbage heads growing at ambient temperature. These results show that Chinese cabbage could be negatively affected by high temperature under a future climate change scenario. Therefore, to maintain the high productivity and quality of Chinese cabbage, it may be necessary to develop new high temperature tolerant cultivars or to markedly improve cropping systems. In addition, it would be possible to use the non-invasive fluorescence parameters $F_O$, $F_V/F_M$, and $F_V/F_O$, as well as $F_K$, $M_O$, $S_M$, RC/CS, ETo/CS, $PI_{abs}$, and $SFI_{abs}$ (which were selected in this study), to quantitatively determine the physiological status of plants in response to high temperature stresses.