• Korean Journal of Ichthyology
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• v.13 no.4
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• pp.248-253
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• 2001

An histological study was conducted to determine the initial treatment time and treatment duration in the use of sex-reversal hormones in relation to gonadal development and sexual differentiation in the bagrid catfish, Leiocassis ussuriensis. The primordial germ cell, which could be recognized from one-day-old fry, began to protrude into the peritoneal cavity between the mesonephric duct and the gut. The primordial gonad with a genital ridge was developed at 5~10 days after hatching. Sex differentiation of the ovary was identified by the ovarian cavity and meiotic oocytes from 20-day-old larvae. Testicular differentiation was also identified by spermatogonial cells from 20-day-old larvae. It may therefore be concluded that this species belongs to the differentiated type of gonochoristic teleost.

• Korean Journal of Ichthyology
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• v.22 no.4
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• pp.279-284
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• 2010

Four leptocephali (TL 109.8~129.7 mm) of the family Ophichthidae, collected from Sangju in the South Sea of Korea, were identified using morphological and molecular methods. Our four leptocephali were similar to Ophichthus sp. based on morphological characters: the melanophores present in series of eight gut swellings; total myomeres 144~151; body depth in total length less than 10%; eight or nine black horizontal bands present from anus to caudal fin base. On the other hand, our four leptocephali were identified to Pisodonophis sp. based on 826 base pairs of 12S rRNA gene nucleotide sequences. Our results showed that morphology-based identification did not agree with molecular identification, indicating difficulty in differentiating morphologically between Ophichthus and Pisodonophis leptocephali. We, herein, firstly describe morphological characteristics of Pisodonophis sp. leptocephali from Korea.

• Korean Journal of Agricultural Science
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• v.42 no.3
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• pp.207-213
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• 2015

High-quality protein ingredients have been used in nursery diets, in spite of expensive ingredients, to minimize nutritional deficiency and disease problems. Recent dramatic increases in prices of protein products for nursery diets have exacerbated the challenge. Spray-dried egg may be a part of the solutions. Therefore, this review describes the value of spray-dried egg in nursery diets as a high-quality protein source. Spray-dried egg is egg by-product and is produced by only eggs without shell that are below the USDA Grade B standards. Spray-dried egg is an excellent nutrient source: 1) highly digestible, 2) excellent balance of amino acids, 3) rich content of fat, and 4) high metabolizable energy. These can be attributed to growth of nursery pigs. Beyond the provision of bioavailable nutrients, spray-dried egg also may provide specific physiological benefits. Spray-dried egg contains 1) immunoglobulin antibodies (IgY: IgG in egg yolk) that may attach to intestinal pathogens and excrete them and 2) lysozymes antimicrobial protein that can damage bacteria cell wall. Thereby feeding spray-dried egg may reduce concentration of intestinal pathogen and thus improve potential gut health or enteric disease resistance in nursery pigs. This is important for physiologically immature weaned pigs. Based on these benefits, spray-dried egg is believed to have the same benefits as spray-dried plasma protein and milk products in diets for nursery pigs. Therefore, it is suggested that spray-dried egg has a great potential as a valuable protein source in nursery diets.

• The Korean Journal of Ecology
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• v.14 no.2
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• pp.211-230
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• 1991

The germinatin of e. annuus continued from the middle ofmay to mid-october. The maximum germination occurred on the mid-july. The period bloom of was distingushed amongs the different growth forms ; a orm pr of biennial and a form of pr perennial flowering from the mid-may to mid-september, and a form ps biennial blossom from the beginning of October to earlynovember. the dispersal of seed for(a form pr)occurred from early June to the mid-september. A rotte, germinating from summer to autumn, could classified into several growth forms; individuals without a critical leaf area for bolting until september and October, become a form ps of biennial, whicth did not proceed toreproductive growth unitl the next year, even thought wintering. individuals flowered on 3 years after germination become a form pr of perennial. The growth formular of aform pr of bennial, grown in a pot was w=20.2[1+$3.36{\times}10^3$(-0.062t)]$^{-1}$. The maximum relative growth rate(rgr) was 0.062g/g/day and the maximum net assimlation rate(nar) 0.089g/g/day. Therelative growth among each organ was shown as R=0.12 $T^{1.15}$between the avove-ground part(t) and the below- ground part(r). the relation between the avove-ground part(t) and the ratio of stem weight(wi) was ws/wi=2.56 $T^{0.35}$. n.p.k. was largely distributed on a leaf throughoutthe total growth period. while growing, it tended to decrease on the vegetative organ gut vice versa on the reproductive organ. however, nitrogen was more widely distributed on a leaf then in the reproductive organ.

• Journal of Aquaculture
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• v.11 no.3
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• pp.401-419
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• 1998

The structure of benthic algal flora and feeding behavior of sea urchins (Anthocidaris crassispina and Hemicentrotus pulcherrimus), were investigated from the eight different locations along the coast of Cheju Island, Korea. Biomass distribution and dominance of the algal communities were studied in relation to the gut contents and population parameters of the sea urchins. As a result, although the largest algal biomass and biological characteristics of sea urchins, such as test diameter, test hight, body weight, gonad weight, etc. This inhdicated that sea urchins would not be dependednt sorely on the abundance of algal foods, and they might feed on other food items. In order to know such a trend with regard to food selectivity, the diets consumed by sea urchins were analyzed, and it was found that they were composed of benthic and drifted algae, various animal components (sponges, bryozoans, crustaceans, and various unidentified capsulated eggs, etc.) and biets turned out to be smaller than might be expected, and it is postulated that sea urchins were not likely to be the major grazing animals for the formation of algal bed and also canopy deterioration, so-called "white incrustation."

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.217-224
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• 2011

The seven leptocephali (14.6~68.0 mm in total length) of the family Ophichthidae, from the East Sea of Korea, were identified using 12S rRNA 861-bp sequences and their morphological development were described. Our seven leptocephali were identified to Echelus uropterus based on genetic distance (d=0.000) being well consistent with that of adult E. uropterus. Our seven leptocephali of E. uropterus are characterized by morphological combinations: caudal fin present; the melanophores present in series of nine gut swellings; total myomeres 154~158; body depth in total length less than 10%; eight black horizontal bands present from anus to caudal fin base. Our morphological and molecular results suggest that E. uropterus may be an intermediate group between subfamily Ophichthinae and Myrophinae.

• Advances in pediatric surgery
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• v.7 no.1
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• pp.46-53
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• 2001

To understand the current status of neonatal surgery in Korea, a survey was made among the 36 members of the Korean Association of Pediatric Surgeons. The response rate was 75 % (26 surgeons in 20 hospitals). Five hundred fifty three neonatal surgical patients treated in 1999 were analyzed. Regional numbers of patients were closely related to the regional population in most areas. Ano-rectal malformations (17 %), pyloric stenosis (16 %), Hirschsprung's disease (13 %), atresia/stenosis of the gut (11 %), esophageal atresia (8 %) were the most common anomalies treated. The majority of operations were done within the first week of life. Seventy one per cent of cases were major life threatening or so-called neonatal index cases. Over-all mortality was 8 per cent. Higher mortality was observed in patients with diaphragmatic hernia (26 %), gastro-intestinal perforation (18 %), NEC (18 %), and esophageal atresia(14 %). Higher mortality was observed in patients with extremely low birth weight (33%) and low birth weight (18 %). Associated anomalies were observed in 20 %. Prenatal ultrasound was performed in 36 per cent with sensitivity of 20 %. Result of this study was compared to the previous report (1994) and that of Japan (1998).

• BMB Reports
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• v.38 no.5
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• pp.571-576
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• 2005

Cytokines are proteins produced by many different cells of the immune system and play a significant role in initiating and regulating the inflammatory process. In this research, an important cytokine, interleukin-10 (IL-10) gene, has been identified and characterized from zebrafish (Danio rerio) genome database. Zebrafish IL-10 is located within a 2690 bp fragment and contains five exons and four introns, sharing the same organization with mammalian IL-10 genes. An open reading frame of 543 bp was found to encode a putative 180 amino acid protein with a signal peptide of 22 amino acids, which shares 29.7-80.9% homology with amino acid sequences of other known IL-10. The signature motif of IL-10 is also conserved in zebrafish IL-10. The predicted transcript was finally confirmed by sequencing of cDNA clones. Multi-tissue reverse transcriptase PCR (RT-PCR) was performed to examine the tissue distribution and expression regulation of this gene in seven organs of normal and lipopolysaccharide (LPS) stimulation zebrafish. The results demonstrated that this gene was expressed slightly in normal kidney, gill and gut, no expression was detected in other four tissues. The expression was clearly upregulated after LPS stimulation. Using the ideal zebrafish model, further study of IL-10 characterization and function may provide insight on the understanding of the innate immune system.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.25-34
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• 2002

In view of increasing environmental pollution, the organic farming in animal production is becoming increasingly urgent. The problems of veterinary medicine have not diminished through the most dangerous epidemic diseases. Organic farming attempts to function in harmony with the environment. The first criterion of the organic farm is that the animal must be self-sustaining. Their food must be produced to a large extent on the farm. The position of ruminants in biological systems is determined by the fact that this group of farm animals is provided with a digestive system which optimizes the utilization of the products of gut microfloral fermentation. The cattle do not require large amounts of concentrate feeling nor gross ugly farm building for intensive rearing. The economic profitability of a cow depends. on the first instance, on the level of milk production and the number of lactations. The length of life is an important factor since the tilde to maturing is relatively high in a cow. The result is that dairy cows in organic farming have greater length of live, and produce more milk in their life time than the shorter lived high input cow. This paper. therefore, discussed the problems of modern cattle farming and development trends of organic farming in Germany and Korea.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.416-426
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• 2006

The purpose of the study was to investigate the perception and preference of chungkukjang in the middle school students under school meal service. For the investigation, 538 third-grade students in Seoul area were surveyed by a questionnaire and the data were analyzed by the SAS package. The result showed that 81.3% of the surveyed students responded the awareness of chungkukjang, and the motives of their interest in chungkukjang were through home education(60.0%) and mass communication(30.9%). Most students recognized that chungkukjang is the soybean fermented food, healthy food and Korean traditional food. 33.8% of students responded that chungkukjang jjigae served at the school meal service was not tasty. It also revealed that male students had more preference for chungkukjang jjigae than female students. Among the 22 kinds of new chungkukjang menu served at the school meal service in the future, 10 kinds of menu (chungkukjang samgeobsal gui, samgeobsal chungkukjang bockum, chungkukjang sauce dakk gui, chungkukjang dongasmali, chungkukjang sogogi janggug, chungkukjang kimchi bokgumbab, chungkukjang bajirak kalguksu, chungkukjang kimchi buchim, chungkukjang sangsun gut, chungkukjang bibimbab) were highly preferred foods by male students. Therefore, in order to make middle school students take the chungkukjang foods with pride by increasing their perception and knowledge of them, the family should give them many opportunities to eat chungkukjang foods. The school also should try to use more chungkukjang foods in the school meal service, and try to improve in cooking process to make more tasty chungkukjang foods fur teenagers.