• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.405-412
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• 1991

Whitefish(Coregonus clupeaformis) and Burbot(Lota iota) muscle was filleted, treated with dipotassium phosphate(pH 8.0) by means of high pressure injection method, and finally stored at $-l2^{\circ}C$ for 3 months. Factors, the pH, moisture content, and total amount of collagen were analyzed on the samples before and after the frozen storage. The pH of the sample showed substantially higher values in the phosphate treated muscles than the controls and decreased after 3 months storage in all of the whitefish and burbot samples, there was no significant differences in the moisture content between the control and treated but some reduction occurred during frozen storage. The amount of total collagen in the tail sections of burbot was significantly high comparing with head sections and hardness of the tail section also showed high values which indicated that total collagen might be related to the texture of fish muscle. However, in the case of whitefish the effect was not apparent. The effects of these factors on the hardness determined by Instron texturometer were analyzed through standardized multiple regression. A specific factor was not apparent to the texture of white fish while pH showed the highest correlation to the hardness of the burbot muscle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.733-739
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• 2014

To develop an effective use for poor-quality individually quick-frozen (IQF) oysters Crassostrea gigas stored for a long period, the extract conditions, quality characteristics, and optimum reaction flavoring (RF) conditions of a complex extract from these IQF oysters were investigated. The moisture, pH, and volatile basic nitrogen contents of IQF oysters stored for 18 months (18M-IQFO) were 77.9%, 6.32, and 17.9 mg/100 g, respectively. Three different kinds of extract were prepared from 18M-IQFO: a hot-water extract (HE), scrap enzymatic hydrolysate (EH), and complex extract (CE). The respective extracts contained 5.5, 8.6, and 6.6% crude protein and 281.7, 366.0, and 343.0 mg/100 g amino nitrogen, and had 811, 359, and 1,170 mL/kg extraction yields. The CE was superior to the traditional HE in terms of the extraction yield, amino-nitrogen content, and organoleptic qualities, except for the odor. To improve flavor via the Maillard reaction, the reaction system used to produce a desirable flavor comprised CE (Brix $30^{\circ}$), 0.4 M glucose, 0.4 M glycine, and 0.4 M cysteine solution (4:2:1:1, v/v). The reaction time and pH were the independent variables, and the sensory scores for baked potato odor, masking shellfish odor, and boiled meat odor were the dependent variables. The surface response methodology (RSM) analysis of the multiple responses optimization gave a reaction time of 120.6 minutes and pH 7.33 at $120^{\circ}C$. The reaction improved the flavor of CE considerably, as compared to that of the unreacted extract.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.221-230
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• 2019

Barbel steed (Hemibarbus labeo) is a small freshwater fish species as semi-bottom dwellers distributed in eastern Asia. We carried out characterization of the cytochrome c oxidase subunit I (COI) gene from the mitochondrial DNA of H. labeo in the Sumjin River to identify the phylogenetic location of H. labeo in the genus Hemibarbus and Cyprinidae. Multiple alignment of the 577 bp COI sequence revealed high sequence homology (99~100%) between Seomjin River H. labeo. The nucleotide sequence similarity between H. labeo (HD1) and H. mylodon was 88.91% and that of H. longirostis was 88.81% among the three species found in Korea. In addition, the nucleotide sequence similarities of H. maculatus, H. meditus, H. umbrifer and H. barbus showed 98.97%, 97.20%, 96.87% and 98.85%, respectively. Phylogenetic analysis on seven species of the genus Hemibarbus showed that the H. labeo collected in this study formed two clades. One of which consisted of Hadong, Imsil, Kangjin. The other one formed a step with HD2, HD8 and HD9 of Hadong and the H. labeo reported in Busan, Asan and Seoul, Korea. Phylogenetic position of the H. labeo among Cyprinidae showed 0.143 for the evolutionary distance from Zacco platypus and 0.006 for the H. maculatus. In addition, the genetic position of the H. labeo among 28 species of Cyprinidae was found to be located in Group I, including Gobioninae fishes. The results of this study will provide key genetic information for the taxonomic comparison in Cyprinidae and study of model fish for pollution monitoring in freshwater environments.

• Journal of Mushroom
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• v.20 no.4
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• pp.241-248
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• 2022

To elucidate how cultivation temperature affected various traits including pileus color, yield and morphology of Pleurotusspp. Main results were as follows. Pileus lightness of all cultivars of Pleurotustested became higher as cultivation temperature increased, while those of Santari, Hwang-geumsantari and Sunjung at 21℃ were lower than at 18℃. Redness and yellowness of pileus decreased as cultivation temperature increased; those of chromatic pileus cultivars showed noticeable difference. Yellowness of cultivar with chromatic pileus was higher than that of cultivar with achromatic pileus. Yield was increased as cultivation temperature increased, Wonhyeung 1ho; low temperature favored cultivar showed high yield when it was cultivated at low temperature andno fruiting body at 21℃. Valid number of stipes were generally higher at 18℃, and its correlation coefficient with yield was low. Length and stipe thickness changed consistently (larger and thicker) upon cultivation temperature; the coefficient of determination(R²) 0.514 for lengthof Heuktari and 0.963for stipe thickness of Santari were high. Correlation coefficient of one trait was highly related with multiple traits. In the future, we will conduct research on the changes of expressed genes involved in the pigments for pileus color by RNA expression analysis.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.131-140
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• 2013

Offspring of 14 sows were used to evaluate the effect of yogurt substituted for creep feed on growth performance, diarrhea score and blood profiles. The piglets of sows were randomly allocated into 1 of 2 treatments (1 treatment separated piglets of 7 sows). The dietary treatments were as followed: CF, creep feed; YG, yogurt. The creep feed and yogurt diets were given from 3 d after piglets were born to the day of weaning (21 d after piglets were born). The body weight and feed consumption were weighed and recorded at d 0, 7, 14, and 21 after piglets were born for calculating average daily gain (ADG) and average daily feed intake (ADFI). At the weaning day, two piglets were randomly chosen from each pen and bled via jugular venipuncture to obtain blood samples for WBC and IgG measurement. All data were subjected to the GLM procedures of SAS (2002) as a randomized complete block design, with pen as the experimental unit. Differences among dietary treatments were separated by Duncan's multiple range test, and P < 0.05 was considered statistically significant. No significant difference (P > 0.05) were observed in number of born piglets, weaning pigs, survival rate, body weight of piglets at d 0, 7, 14, and 21, ADG and ADFI. At d 21, piglets fed with creep feed had a higher (P < 0.05) IgG compared with piglets fed with yogurt. No significant difference (P > 0.05) was observed in WBC among treatments at d 21. In conclusion, yogurt substituted for creep feed had no adverse effect on growth performance in lactating piglets.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1625-1625
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• 2001

The calibration equations for Brix value determination of intact mango were developed using the NIR spectra in a short wavelength region from 700 to 1100 nm. Multiple linear regression (MLR) and partial least square regression (PLS) was used for the calibration. It was found that the best wavelength region for PLS calibration from 900 to 1000 nm was similar to the wavelength region selected by MLR from 906 nm to 996 nm. Both MLR and selected region PLS provided sufficiently accurate prediction equations for Brix determination of intact mango. For MLR, the prediction results were SEP = 0.45 Brix and Bias = -0.04 Brix while PLS prediction results were SEP : 0.46 Brix and Bias = -0.2 Brix. It was concluded that MLR and PLS would have similar abilities in making calibration equation for Brix determination of intact mango if the appropriate wavelengths or wavelength region were selected. The appropriate wavelength region for PLS regression could be assumed by using the wavelength region selected by MLR in place of random selection, The relationship between calibration results of MLR and PLS regression is discussed.

• Korean Journal of Veterinary Service
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• v.36 no.1
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• pp.37-44
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• 2013

The ecologically and economically important honeybee species are susceptible to infections by various pathogens. This study was investigated to detect infectious pathogens in honeybee colonies reared in eastern Gyeongbuk province by PCR in 2010~2011. A total of 11 infectious pathogens, including 6 viruses, 2 bacteria, 2 fungi, and 1 parasite, were investigated in honeybee colonies suffering from symptoms of sudden collapse, depopulation, or paralysis. The infectious pathogens and infection rates among 24 honeybee colonies detected were as follows: sacbrood virus (66.7%), deformed wing virus (4.2%), black queen cell virus (12.5%), Kashmir bee virus (29.2%), American foulbrood (41.7%), European foulbrood (12.5%), stonebrood (45.8%), chalkbrood (4.2%), and Nosema (33.3%), respectively. Since the coinfection rates of multiple pathogens were detected high in honeybee colonies reared in eastern Gyeongbuk province, large-scale investigation and appropriate control programs need to be established in this region.

• Animal cells and systems
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• v.8 no.1
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• pp.33-40
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• 2004

Reproductive cycle and spawning rhythm with lunar cycle of the ascidian, Halocynthia hilgendorfi ritteri were investigated by histological examination. The specimens were sampled in the coastal waters of Yongdam, northwest of Jeju Island, Korea, from November 2001 to January 2003. H. hilgendorfi ritteri is a synchronous hermaphrodite; the gonads are located in the mantle. The reproductive cycle can be grouped into the following successive stages in the ovary: growth (February to June), vitellogenesis (April to September), mature (July to December), spent (November to February), and recovery (December to April). Likewise, in the testis, the stages observed were: growth (October), mature (October to December), spent (November to February), and resting (January to September). Major spawning probably occurs between November and January, when water temperatures decrease. The histological observations of the gonads suggested that this species is a multiple spawner during the spawning period. Spawning occurred between the new moon and full moon, and again between the full moon and new moon, suggesting that the spawning rhythm is influenced by the lunar cycle.

• Journal of Forest and Environmental Science
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• v.24 no.3
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• pp.143-149
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• 2008

We conduct economic analysis of the snow damage on sugi (Cryptomeria japonica) forest stands in Toyama Prefecture, Japan. We utilize a single tree and distant independent growth simulator called "Silv-Forest." With this growth simulator, we developed an optimization model by dynamic programming, called DP-Silv (Dynamic Programming Silv-Forest). The MS-PATH (multiple stage projection alternative technique) algorithm was embedded as a searching algorithm of dynamic programming. The height / DBH ratio was used to constrain the thinning regime for snow damage protection. The optimal rotation age turned out to be 65 years for the non-restricted case, while it was 50 years for the restricted case. The difference in NPV of these two cases as the induced costs ranged from 179,867 to 1,910,713yen/ha over the rotation age of 20 to 75 years. Under the optimal rotation of 65 years, the cost became 914,226 yen/ha. The estimated annual payment based on the difference in NPV, was from 9,869 yen/ha/yr to 85,900 yen/ha/yr. All in all, 10,000 yen/ha/yr to 20,000 yen/ha/yr seems to cover the payment from the rotation age of 35 to 75 years.

• Journal of Aquaculture
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• v.22 no.1
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• pp.83-91
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• 2009

The Korean doty barbel Hemibarbus mylodon (Cypriniformes; Cyprinidae) is a critically endangered freshwater fish species mainly because of its natural habitat degradation. Three full-length complementary DNA (cDNA) clones representing different muscle actin isoforms were isolated and characterized. The three muscle actin isoforms were 1,294-1,601 bp long with the identical open reading frames of 1,134 bp with the deduced amino acid residues of 377. They showed 83.9-87.2% identities in the coding nucleotide level and 96.8-98.1% identities in the amino acid level. Phylogenetic analysis with the coding nucleotide sequences revealed that three muscle actin isoforms of H. mylodon formed strongly supported monophyletic groups with one of cypriniform skeletal $\alpha$-actin (acta1), cypriniform aortic $\alpha$-actins (acta2), and uncharacterized Danio rerio muscle actin isoform/Salmo trutta slow muscle actin (a novel muscle actin type). Our phylogenetic tree further suggested that cypriniform acta2 only showed the orthologous relationship to tetrapod acta2. Other multiple actin isoforms from diverse teleostean taxa were however clustered to no tetrapod orthologs, i.e., acta1, cardiac $\alpha$-actins (aetc1), acta2, and enteric $\gamma$-actin (actg2). This result strongly suggested that teleostean muscle actins have experienced different and complicated evolutionary history in comparison to mammalian counterparts.