• BMB Reports
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• v.33 no.4
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• pp.326-331
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• 2000

Acidic chitinases from the gizzards of a broiler were purified to homogeneity, using precipitation with $(NH_{4})_{2}SO_{4}$, ion exchanger chromatography, gel filtration, chromatofocusing and hydrophobic interaction chromatography. The enzymes, GAC1 and GAC2, were purified 180- and 194- folds with a recovery of 4.9% and 2.7%, respectively. The molecular mass of GAC1 and GAC2 were 48.2 kDa and 57.8 kDa, respectively. Chromatofocusing resulted in a pI of 3.1 for both enzymes. The purified enzymes were endochitinases that were devoid of ${\beta}-N-acetylglucosaminidase$ and lysozyme activity. Kinetic studies using $[^3H]chitin$ indicate that GAC1 has a $K_m$ and $V_{max}$ of 1.97 mg/ml and 185 mg/mg protein/h, respectively. The GAC2 has a $K_m$ and $V_{max}$ of 0.42 mg/ml and 92.3 mg/mg protein/h, respectively at optimal pH and temperature (pH 5.0 and $60^{\circ}C$). When the pentamer and hexamer of N-acetylglucosamine (GlcNAc) were used as a substrate, the major product by GAC1 was the dimer of GlcNAc with a differential accumulation of the monomer and trimer, depending upon the substrate. However, the GAC2 produced the dimer and trimer in an equal quantity, regardless of the substrate used. The first 9 $NH_2-terminal$ amino acid residues of the purified gizzard chitinase GAC1 and GAC2 shared a 100% homology. The first 25 $NH_2-terminal$ amino acid residues of GAC1 also shared 55-60% homology with animal chitinases and some animal proteins, such as whey protein and oviduct-specific proteins. However, little homology was found with either microbial and plant chitinases, or egg white lysozyme.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.3
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• pp.284-288
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• 2018

The scuttle fly central nervous system (CNS) is unobservable during egg and larvae instar stage 1. During days 2~3 of larvae instar stage 2, the left and right hemisphere of the brain can be observed. Below the brain, the subesophageal ganglion (SOG) connects to the ventral nerve cord (VNC). During days 3~5 of larvae instar stage 3, the CNS enlarged slightly with no other changes. During days 1~3 of the pupal stage the CNS moved to the head with no distinguishable changes from the previous stage. During days 4~6 of the pupal stage, the left and right hemisphere of the brain had fused into one mass and the optic lobe (OL) located on the side of the brain completed its development. During days 7~9 of the pupal stage, the OL began to show eyeball pigment. The SOG was connected to the brain and the VNC began to separate, which was accompanied by an increase in nerve fibers. During days 10~12 of the pupal stage, the brain of the CNS and VNC was clearly distinguished and the brown pigmentation of OL became darker. During days 13~15 days of the pupal stage, the separated brain and VNC became connected by thin nerve fiber. The VNC began to separate into two with a greater increase in nerve fibers. The adult fly showed similar features to the previous stage, but the brain was located in the head and the VNC in the chest.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.46-53
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• 2010

Spawning behavior and early life history of the tuman river sculpin, Cottus hangiongensis were studied in the laboratory and in the field at Wangpi Stream, Gyeongsangbuk-do, Korea, from January to December, 2007. The spawning ground was in the lower Wangpi Stream, which is a shallow region about 40cm or less in depth. During the spawning period, from March to April, mature males made nest cavities under stone 10 which they led a gravid female. The male and female then turned upside down, and spawning and fertilization occurred onto the ceiling of the nest cavity. After spawning, the male chased the female from the nest and mated with several other females. Fertilized eggs were spherical in shape, demersal, adhesive, transparent and yellow in color, measuring 1.86 mm (1.79~1.93 mm) in diameter. A mean of 17(12~22) various-sized oil globules were counted in the yolk. Granular materials formed a mass in the yolk. Fertilized eggs hatched at 256 hrs, 10 minutes after the morula stage under water temperature of $15.0{\sim}18.0^{\circ}C$. Newly hatched larvae 9.34 mm (9.02~9.69 mm. n=10) in total length (TL) had a large yolk At 14 days after hatching, larvae 11.40 mm (11.07~11.72 mm, n=10) in TL transformed to the postlarval stage. At 41 days after hatching, postlarvae of 18.42 mm (17.31~18.62 mm, n=10) in TL had reached the juvenile stage. The result of this study indicate that Cottus hangiongensis has the spawning ground in the lower stream and the amphidromous life history which is the different from that of Cottus poecilopus.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.300-307
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• 1995

This study was carried out to investigate the life cycle of Cephonodes hylas (Linne), that is damaging to Gardenia jasminoides Ellis in the seedbed at Namhae during 1984 and 1985. Results are summarized as follows. The eggs were laid in mass on the leaf surface of the host plants. The oviposition period lasts for 26 days after late-May. The average number of eggs and average hatching rate were 20.36 and 97.61% , respectively. It takes 14-16 days until hatching. The egg shape was oval which its size was 1.01 mm in diameter and 1.48 mm in length. The body length of each larval instar from the 1st to the 5th were $3.52\pm$1.01, $6.46\pm$0.45, $13.19\pm$4.27, $24.08\pm$2.22 and $43.71\pm$5.62 mm, respectively. The average weight of each larval instar were $13.34\pm$2.41, $29.83\pm$6.88, $76.64\pm$31.31, $292.09\pm$107.70 and 2,$144.84\pm$760.70 mm, respectively. The larval period was observed from July to October, and total duration of larval stage was 116 days in which duration of each larval instar from the 1st to the 5th were 12, 36, 32, 16 and 20 days, respectively. During larval stage, a larvae feed on 17~18 seedlings. The 5th instar larvae built its place in soil for overwinter and became pupa. The body length of pupa was 33.6 mm and average weight was 2,032 mg Adult was emerged from overwintened pupa from mid through late-May in the followings year. The sex ratio of female was 42.82% and the color ratio of brown was 89.93%.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.53-57
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• 2009

Biological Characteristics of Lycorma delicatula and insecticidal activity of some insecticides against nymphs of L. delicatula was investigated. Nymph of L. delicatula had 4 instars, and color of body was black. There were white spots on the body of 1st-3rd nymph. Upper body became red at 4th nymph. Adult forewings were brownish, and had black spots. Color of hind wing were red. The egg mass was covered with a yellowish brown secretion. The adult of L. delicatula emerged once a year. Among test insecticides, deltamethrin 1% EC and fenitrothion 50% EC showed very quick and strong insecticidal activity against the 2nd-3rd nymphs of L. delicatula. Imidacloprid 4% SL and clothianidin 8% SC showed 100% insecticidal activity at 24h after treatment. Thiacoprid 10% SC revealed the weakest insecticidal activity among the insecticides tested.

• Korean Journal of Ichthyology
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• v.29 no.4
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• pp.235-243
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• 2017

Reproductive characteristics of Rhodeus pseudosericeus (Pisces: Acheilognathinae) was investigated at the Heukcheon (River), Yangpyeong-gun, Gyeonggi-do, Korea from January to July in 2012. This fish prefers heavily vegetated stagnant pool with Phragmites japonica and Salix koreensis and area with high proportions of sand and mud. The standard length of the population indicated that 13~22 mm group is 0-year old, 30~45 mm group is 1-year old, 45~55 mm group is 2-year old and 45~70 mm group is more than 3-year old (June in 2012). The sex ratio of female to male was 1 : 0.80. The spawning season was from March to June with water temperatures in the range $11.0{\sim}26.2^{\circ}C$. The embryos were found with no egg mass in Unio douglasiae sinuolatus and the number of those was 1~22 ($5.8{\pm}5.51$). The number of the embryos found in each of the four parts of the mussel gill was 1~9 ($2.7{\pm}2.16$) in left outer, 1~2 ($1.5{\pm}0.71$) in left outer, 1~5 ($1.8{\pm}1.79$) in left outer and 1~22 ($5.8{\pm}5.51$) in left outer.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.371-384
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• 2007

This study was conducted to examine nutrient intake status and iron food sources by dietary iron density of high school girls in Seoul. The subjects of 226 girls were divided into High group (${\geq}$ 6 mg/1,000 kcal, N=115) and Low group (< 6 mg/1,000 kcal, N=111) by dietary iron density. The nutrient intake data obtained by 24-hour recall method were analyzed by Can Pro 3.0 software. Mean age of all subjects was 16.4 years old, heights and weights of High group and Low group were 164.5 cm, 53.4 kg and 161.7 cm, 51.7 kg, respectively. The body mass index (BMI) of High group and Low group was 20.5 kg/m$^2$ and 19.8 kg/m$^2$, respectively. Most nutrient intakes except energy and lipid intakes of High group were higher than those of Low group. High group showed significantly higher intakes of total iron, vegetable iron and animal iron than Low group. Ca and folate intakes of High group were under 75% of the recommended intake (RI) and Ca, iron, folate and vitamin C intakes of Low group were under 65% of RI. The percentage of subjects who consumed iron less than estimated average requirements (EAR) were 40.0% in High group and 77.5% in Low group. Total food intakes of High group showed higher than that of Low group. Total animal food intakes were significantly higher and total vegetable food intakes were significantly lower in Low group than those of High group. Iron intake from meats, fishes, shell fishes and seasonings were significantly higher in High group than Low group. Iron intake from milk and dairy products were significantly lower in High group than Low group. Major food sources of iron were rice, bean curd, pork, and egg in order among both groups.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.4
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• pp.272-279
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• 2019

The study was conducted to evaluate the seminal attributes and cryobanking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 10⁶ cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN₂) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 10⁶ cells/mL vs. 1060.0 ± 44.3 × 10⁶ cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.295-301
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• 2015

We investigated mycophagous ladybird, Illeis koebelei from 12 species of plants infected with powdery mildew in Gyeonggi-do, Korea. The pear tree, Pyrus ussuriensis var. macrostipes (Nakai), was most preferred by I. koebelei. This species was found from early July to early November in pear orchards. There was no entomophagous trace in the gut of I. koebelei without powdery mildew spores in a microscope. All stages except egg and pupa are obligate mycophagous, and the feeding potential is ranked as follows: fourth instar, adults, third instar, second instar, and first instar. Feeding amounts of each stage of I. koebelei were 45.6, 144.4, 372.2, 628.1, and $473.7mm^2$ of cucumber powdery mildew per day. Fourth instar larvae showed highest consumption of cucumber powdery mildew. Developmental periods of four larval instars and adults feeding cucumber powdery mildew were 1.2, 2.3, 2.3, 4.6, and 37.7 days, respectively, at $25^{\circ}C$. In this study, we could not determine the feeding potential of I. koebelei against the cucumber powdery mildew; therefore, and further studies are required to elucidate the potential of this species as a biological control agent, e.g., mass rearing, selection of low toxic chemical agents for Integrated Pest Management (IPM), and control techniques against powdery mildew in agro-ecosystems.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.174-184
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• 2011

The purpose of this study was to evaluate nutrients intakes, glycemic index (GI), glycemic load (GL) according to obesity index in elementary school students. The study subjects included 229 elementary school students (boys=108, girls=121) who were divided into 3 groups consisting of an underweight group (obesity index<-10%, n=58), a normal weight group (10%${\leq}$ obesity index<10%, n=130) and an overweight group (obesity index${\geq}$10%, n=41) by their obesity index. The nutrient and food intakes data obtained by a 3-day food record were analyzed. Daily dietary GI and GL values were calculated from the 3-day food record. The average age of the subjects was 11.9 years. The mean daily energy intake was 2,186.8 kcal in the underweight group, 2,123.5 kcal in the normal weight group, and 2,174.2 kcal in the overweight group. The intakes of calcium and animal calcium per 1,000 kcal in the overweight group were significantly lower than in the underweight and normal weight groups (p<0.01, p<0.05), and fruit, egg and milk intakes in the overweight group were lower than those in the underweight group (p<0.05, p<0.05, p<0.05). The mean daily dietary GI of the underweight, normal weight, and overweight groups were 67.7, 68.4 and 69.5, respectively (p<0.05). The mean daily dietary GL of the underweight, normal weight, and overweight groups were 212.8, 208.1 and 213.3, respectively. The major food source of dietary GI and GL in the three groups was rice. Other major food sources of dietary GI were croquettes, hand-rolled noddle soups, instant noddles, milk, and rice cake. Dietary GI was not significantly correlated with weight, obesity or body mass index, when adjusted for energy, carbohydrate, and dietary fiber. However, GL adjusted to energy, carbohydrate and dietary fiber tended to correlate with obesity index (r=0.126, p=0.059). These results suggest that dietary GI and GL have possibility affecting obesity-related indicators in elementary school students.