• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.2
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• pp.115-121
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• 2002

To develop a new method of conjugation and to determine the distribution of R plasimds, we isolated multi-drug resistant strains from fish pathogenic bacteria in the farms of south and east seacoasts of Korea. Out of the 134 isolates examined, 10 showed resistance to chloramphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid and kanamycin. One out of 10 multi-drug resistance bacteria, Vibfio damsela JE1 (V. damsela JE1), contained transferable R plasmid of chlorarnphenicol- tetracycline resistance genes and other nucleic acids encoding ampicillin and kanamycin resistance. The presence of the R plasmid was confirmed by conjugation using the chromocult medium (CC) as a selective and differential medium for transconiugants with identification based on the growth or colors of the colonies. The frequency of R plasmid transfer with filter mating method was come out much higher than that of broth mating method and appeared to be dependent upon the mating time and temperature. The optimum conditions for filter mating method were found to be 30$^{\circ}C$ and 24hrs as mating temperature and period, respectively, Moreover, donor cells with R plasmid, both isolate and standard bacteria, were shown to have an ability to transfer the plasmid against Escherichia coli K-12 HB101 (E. coli HB101) and Edwardsiella tarda (E. tarda) RE14 at fairly high frequencies, finally, we isolated 3 isolates of Sphingomonas sp., carrying R plasmid from 12 multi-drug resistant bacteria in normal microflora of the flounder (Paralichthys olivaceus) group used for the isolation of V emsela JE1 four months before. The same size and gene transfer chayateristics of R plasimds with those of V damsela JE1 confirmed that normal microflora have the reservoir activity for R plasmid in natural aquatic environment.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.54-58
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• 2016

In natural conditions, the black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), colonizes in warm temperate regions, and is active in Korea from May through October. Information on black soldier fly rearing, which is affected by seasonal factors in Korea, is limited. This species colonizes and oviposits in a wide variety of decomposing vegetable and animal matter. For mass rearing of black soldier flies, the egg deposition methods are dependent on sunlight and oviposition sites. In this study, we investigated the substrates and oviposition sites preferred by black soldier fly in artificial rearing system. Our results showed that as black soldier flies prefer mating under sunlight, they prefer ovipositing at sites where adequate sunlight and food substrate are available. Further detailed research is required to develop methods for artificially rearing black soldier fly throughout the year in Korea.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.33-37
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• 2005

Sasa borealis Makino is distributed in East Asia such as Korea, Fushun in China, and Japan. Especially the species is only found in the high altitude (above 600 m) at mountain of cold regions including The Korean Peninsula. The level of genetic diversity and population structure of this species was surveyed using starch gel electrophoresis at putative five enzyme loci from three natural populations in Korea. Results from twelve loci indicated that genetic diversity was low. In addition, analysis of fixation indices revealed a substantial heterozygosity deficiency in some populations and loci. The reasons for the deficit of heterozygosity may be partly considered inbreeding, small population sizes, and mating of demes. S. borealis can reproduce extensively by producing rhizomes and potentially by sexually produced seeds. Rhizomes are generally long, prostate stems rooting at the nodes.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.191-199
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• 2021

Salmon oil (SO) could be used as a great source of ω-3 fatty acids in pig diet. The purpose of the study was to investigate the SO effect on production performance of sows and their offspring. 48 lactating sows (Landrace × Yorkshire) from Dankook University experimental farm were used in this study. Sows were conceived using either guided natural mating or by artificial insemination. Pregnancy diagnosis was confirmed by ultrasonography on day 25 after mating. Sows and their offspring were assigned randomly to 1 of 2 treatments. Treatments included: 1), control (CON); 2), control + SO 0.5% (CS). The inclusion of SO did not affect (p > 0.05) the litter size throughout the experiment. No difference (p > 0.05) was observed on the average daily feed intake (ADFI), chest circumference, estrus interval and sow backfat thickness between CON and SO treatments. Dietary SO supplemented diet reduced (p < 0.05) body weight loss during lactation compared with control treatment. Pigs fed SO supplemented diet did not affect (p > 0.05) the fecal scores during lactation compared with those fed control treatments. Sows fed SO supplemented diet led to a higher (p < 0.05) initial weight, weaning weight and average daily gain of piglets than those fed control diets. No difference (p > 0.05) was observed on piglet survival and fecal scores throughout the experiment. Inclusion of SO could reduce the body weight loss of sows and improves piglet growth during lactation, indicating SO has beneficial effects for pigs.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.477-486
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• 1996

The freshwater goby, Micropercops swinhonis ($G\"{u}nther$) was studied on the spawning behavior and egg develeopment at the two areas of Chollabukdo, Korea from March to May 1995. Egg mass attached to a layer under stones and the inner wall of waterplant, Cyperus. Spawning behavior was divided in to 1) premating stage: selecting spawning sites and formation of territory by male, 2) mating stage: enticement with zigzag-like dance and intermittant shaking of head by male and fertilization, 3) postmating stage: fanning, guarding and cleaning the nest by male. The eggs were transparent and spherical in shape, measuring $0.9\times1.4mm$ with yellowish yolk sac and many oil globules. Hatching began in about ten days after fertilization at water temperature $16~20^{\circ}C$. The newly hatched larvae were 3.8~4.0 mm in total length with 30 myomeres and their mouths and anuses were opened. Melanophores appeared at the air-bladder and the ventral side of caudal region.gion.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.917-922
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• 2003

This study was conducted to investigate effects of farm, type of sow Landrace${\times}$Yorkshire, LY; Yorkshire${\times}$ Landrace, YL; Yorkshire${\times}$Yorkshire, YY and multi-cross bred sow, MBS), parity, farrowing year, farrowing season and mating method on reproductive traits such as total number born per litter, number of born alive per litter, number of weaned per litter, number of mummified per litter, number of stillbirth. The Reproductive Records of 3,387 litters from January, 1999 to September, 2002 were obtained from four pig farms managed by Electronic Data Processing(EDP) system. Reproductive performances for two types of F1 Sows(YL and LY) were estimated as 11.34${\pm}$0.266 and 11.57${\pm}$0.263 heads for total number of born per litter, 10.56${\pm}$0.216 and 11.81${\pm}$0.251 heads for number of born alive per litter, and 10.05${\pm}$0.131 and 9.96${\pm}$0.153 heads for number of weaned per litter, respectively. These records are significantly higher(P〈0.05) than those of YY and MBS. However, number of mummified per litter, number of stillborn per litter, number of dead by diarrhea per litter, number of dead by other reasons during lactating period per litter and estrus interval did not show significant difference between types of sows. There were more total number of born per litter and number of weaned per litter in year 2001 than other year. As year passed, number of dead by crush per litter, number of dead by diarrhea per litter and number of dead by other reasons during lactating period per litter reduced from 0.18${\pm}$0.023 to 0.07${\pm}$0.022 head, 0.12${\pm}$0.21 to 0.02${\pm}$0.020 head and 0.43${\pm}$0.041 to 0.22${\pm}$0.040 head, respectively and weaning rate increased from 0.94${\pm}$0.005% to 0.97${\pm}$0.005%. The total number of born per litter and number of born alive per litter were higher(P〈0.05) in the case of mating twice than mating once. The number of weaned per litter, number of mummified per litter and number of stillborn per litter were not significant(P〈0.05) between mating methods. Estrus interval was shorter on the occasion of twice artificial insemination(5.24${\pm}$0.153days) than twice natural mating(6.51${\pm}$0.466days).

• Animal Bioscience
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• v.34 no.5
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• pp.844-854
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• 2021

Objective: The potential of extra virgin olive oil (EVOO), betaine (BET), and ginger (GIN), as natural antioxidants, in reducing negative effects of heat stress on physiological responses, antioxidant capacity, semen quality and fertility of bucks under heat stress were investigated. Methods: Forty adult Animal Production Research Institute line rabbit bucks were distributed randomly into four experimental treatments of ten rabbits each. The first treatment was fed the commercial pellet diet (CPD) without supplementation and served as a control. The other three treatments were fed CPD supplemented with EVOO (300 mg), BET (1,000 mg), and GIN (200 mg) per kg diet for 3 consecutive months during the summer season. Results: Supplementation of EVOO, BET, or GIN improved (p<0.05) the sexual desire, progressive motility, vitality, intact acrosome and membrane integrity, sperm cell concentration, sperm outputs and fertility. Seminal plasma total proteins, globulin, total antioxidant capacity, glutathione and glutathione S-transferase, and initial fructose increased (p<0.05), while total lipids, aspartate and alanine aminotransferases and malondialdehyde decreased (p<0.05) compared with the control. In comparing the natural antioxidants treatments, GIN evoked the largest improvement. Conclusion: The inclusion of GIN (200 mg/kg diet) appeared to improve the sexual desire, semen quality and oxidative stress of bucks. This may be a beneficial supplement for the management of rabbit bucks used in natural mating or artificial insemination.

• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.8-14
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• 2021

Spawning behavior of the endangered Korean fish, Microphysogobio koreensis, was investigated in the Seomjingang (river), Imsil-gun, South Korea, during the spawning season, April to May 2012. The mating system of M. koreensis, a broadcast spawner, was a primitive spawning mode, and involved one male and one female, unlike group spawning fishes. Spawning behavior of M. koreensis in the wild were observed in eight patterns as resting, male chase, body beating, parallel swim, female withdrawal, male competition, spawning and not guard while spawning behavior in the glass tank were verified in six patterns as resting, male chase, body beating, parallel swim, spawning and not guard. In particular, a behavioral attempt of the pre-spawning stage showed more frequently in the wild than in the glass tank. We assume that difference of spawning behavior might be implication on behavioral restrictions in small and narrow indoor glass tank.

• The Korean Journal of Mycology
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• v.25 no.2 s.81
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• pp.111-120
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• 1997

The characteristics of monosporous isolates of winter mushroom [Flammulina velutipes (Curt. ex Fr.)] were investigated to obtain useful breeding materials. Within monokaryons from cultivars which have a white colored fruitbody showed narrow genetic variation, while domestic strains which have a brown colored fruitbody showed wide variation. The mating type of the white strains was A1A2B1B2 genotype, but that of the domestic brown strains were A3A4B3B4. In intra-crossing, the genetic stability of dikaryons mated by monokaryons from white strain was less than that of parents. While in brown strain, dikaryons with high yield and color variation were obtained.

• Journal of the Korean Society of Costume
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• v.50 no.5
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• pp.131-142
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• 2000

The philological consideration of Korean Buddhist Monk's robe and its reviving have been investigated in traditional way. The configuration and colour of Korean Buddhist monk's robes have been properly adapted for an period, territory, and atmospheric phenomena. In case of Korea, introduced Buddhism from China realize modern robe from under the influence of fusion of Chinese ornament culture and Korean traditional ornament culture. As a result of this modern robe has been consisted of a Buddhist monk's robe and a cope. The modem robes has been significantly affected by industrialization, contrary to ancient time taxed robes as public imposts. At present be familiar in mass production we have a preference for the easier way in making and even color forming. In this paper it is focused on dyeing part, which recognized its important in latest time, at first declined according to appearance of chemical dye, evaluated its convenience in use. That is, it is increased natural dye, people begin with recognition of difference of physical properties for dress dyed with chemical pigment and that with natural pigment. In consequence, I have presented that both making colour of gray using traditional method, and three demolished-color prescribed by Buddhist law. Of course, though it become generally know that dyeing of robes occupied significant part of traditional natural dyeing. But in case of religion, it also is important to know symbolical meaning involved in its colour. Most of Buddhism-believers or even Buddhists who actually be dress in robe are without knowing the meaning of colour, or its revealing method. There, I have considered mating three colour of demolished- color included blue, black, and red, and also represented dyeing method of Buddhist monk's robe using both charcoal and ink-spick. From religious font of view, as robes contains involving of blessing, I have an intention of improvement way in dyeing and succession and development of traditional culture through consideration of traditional dyeing method. And I have also intended to restoration the value of robe's colour, disappeared by the time. moreover, I have shown that dyeing with natural pigment is profitable for both environment and sanitary aspect.