• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.61-71
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• 1989

The purposes of this study were to investigate the genetic variations by backcrossing in commercial chickens. Backcrossing was carried out successively back to parent stock (P.S). Heritabilities and genetic correlation coefficients were estimated to verify the genetic variations. The data obtained from a breeding programme with commercial chickens (I strain) were collected from 1955 to 1987 at Poultry Breeding Farm, Seoul National University. Data came from a total of 1230 female offspring. The results obtained are summarized as follows： 1. The general performance ($Mean\pmStandard deviation$) of each trait was $663.94\pm87.11$g for 8 weeks body weight, $1579.1\pm155.43$g for 20 weeks body weight, $2124.1\pm215.3$g for 40 weeks body weight, $2269.1\pm242.94$g for 60 weeks body weight, $168.43\pm12.94$ day for a9e at sexual maturity (SM), $214.52\pm29.82$ eggs , for total egg number to 60 weeks of age (TEN), $61.45\pm3.48$ g for average weight (AEW), $13180.7\pm1823.22$ g for total egg mass to 60 weeks of age(TEM). All traits, except 10 weeks body weight and AEW, were significant for the degrees of backcross (p＜0.01). 2. The pooled estimates of heritabilities derived from the sire, dam and combined variance components were 0.47~0.52 for age at sexual maturity (SM), 0.07~0.37 for total egg number (TEN), 0.40~0.54 for average egg weight (AEW), 0.18~0.27 for total egg mass (TEM). High heritability estimates were found for SM and AEW. TEN and TEM were estimated to be a lowly heritable traits. Heritability estimates from dam components were higher than those from sire components. These differences might be due to non-additive genetic effect and maternal effect. 3. The estimates of heritabilities and standard errors derived from combined variance components for different degrees of backcross were $0.47\pm0.11$ (BCO), $0.42\pm0.16$ (BC1), $0.51\pm0.29$ (BC2) for TEN, $0.59\pm0.20$ (BCO), $0.43\pm0.17$ (BC1), $0.35\pm0.18$ (BC2) for AEW, $0.28\pm0.12$(BC0), $0.20\pm0.11$(BC1), $0.18\pm0.14$ (BC2) for TEM. Heritability estimates for AEW and TEM were decreased by backcrossing while those for SM and TEN remained constant. Since backcrossing contributes to increased homozygosity, the genetic variation of the traits (AEW and TEM) decreased . 4. The pooled estimates of genetic correlation coefficients were -0.55 between SM and TEN, 0.20 between SM and AEW, -0.29 between TEN and AEW, 0.82 between TEM and TEN, 0.31 between TEM and AEW, -0.42 between TEM and SM. The genetic correlation between TEM and TEN was higher than that between TEM and AEW, and it was suggested that egg mass was strongly affected by egg number. Also, age at sexual maturity(SM) contributes to egg mass(TEM). 5. When backcrossing was carried out successively, the genetic correlation between TEM and TEN increased (BC0：0.79, BC1：0.82, BC2：0.91) but those between TEM and SM decreased (BC0：-0.54, BC1：-0.36, BC2：-0.09) with successive backcrosses.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.185-193
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• 2014

To find the influence of water temperature, tank color and illumination in feeding, growth and blind-side hypermelanosis of starry flounder, Platichthys stellatus, in the present study, we performed a series of temperature, background color and illumination intensity test for 180 days (From June to December). The test was done in duplicate at 100 fish/tank (430% of initial covering area [PCA]) with the selected ordinary juvenile flounder (TL $17.3{\pm}0.5cm$, BW $82.5{\pm}0.2g$). The rearing was performed in darkgreen FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 1,000 lux and 230 lux, and in white FRP aquarium tank ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 230 lux of light intensity. We investigated correlation of daily food intake (DFI) with water temperature and salinity, and compared the influences of background colors and light intensity in DFI, food efficiency (FE), growth, survival rate, and ratio of malpigmented blind-side area and ambicolored fish ratio. In DFI, although it was not related with salinity, the amount was significantly decreased under 0.5 g/fish/day in summer and winter season, but was significantly increased over 1.5 g/fish/day in autumn season showing from $10^{\circ}C$ to $20^{\circ}C$ in water temperature. In background and illumination test, DFI, FE and survival rate showed no difference among three groups. The ratios of malpigmented blind-side area and ambicolored fish were also not significantly different among three groups, indicating that the blind-side hypermelanosis of starry may be governed not by background color (or light intensity) but by a genetics external trait inherited from parents.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.157-164
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• 2010

We investigated the influence of carcass traits on carcass price for Hanwoo cow using multiple regression and path analyses. Data for carcass traits and price were collected on mature Hanwoo cow raised in private farms in Kangwon province that were slaughtered in 2008. A total of 96 animals with the average slaughter age of 51 months were used in the current study. Of the carcass traits studied, marbling score (MAR), dressing percentage (DP), and eye-muscle area (EMA) showed moderate and positive correlations with auction price (AP), while correlation coefficients of meat yield index (MINDEX) with AP were low or even negligible. In multiple regression analyses of AP and carcass price (CP) on cold carcass weight (CWT), back fat thickness (BFT), EMA, MAR, and DP, estimates of $R^2$ were 69.86 and 85.43%, respectively. Partial regression coefficients for CWT, BFT, EMA, MAR and DP were -0.028, -0.106, 0.107, 0.814, and 0.075 in the equation of AP and 0.561, -0.060, 0.083, 0.590, and 0.051 in the equation of CP. In path analyses, MAR's total contribution on the variation of AP was largest (0.667), and the total contributions of MAR and CWT on the variation of CP were 0.403 and 0.397. The current study suggested that marbling was the most influential trait on the variation of auction price, and marbling and cold carcass weight were critical traits on the variation of carcass price.

• Korean Journal of Psychosomatic Medicine
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• v.28 no.1
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• pp.63-71
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• 2020

Objectives : The aim of this study was to investigate the impact of clinical and psychological factors on the parental stress of children and adolescents with epilepsy. Methods : Children and adolescents with epilepsy (n=90, age range=6-17 years) completed questionnaires on epilepsy-related variables, children's depressive symptoms (Children's Depression Inventory, CDI), children's anxiety (Revised Children's Manifest Anxiety Scale, RCMAS) and performed the scale for children's intelligence (IQ). Parents who have children and adolescents with epilepsy completed questionnaires on parental stress (Questionnaire on Resources and stress, QRS), parental anxiety (State-Trait Anxiety Inventory, STAI), children's attention problems (Abbreviated Conners Parent Rating Scale Revised, CPRS), and children's behavioral problems (Korean Child Behavior Checklist, K-CBCL). Stepwise regression analysis was performed to determine the significant predictive variables that affect parental stress. Results : In the correlational analysis, duration of seizure treatment (r=0.253, p=0.016), children's IQ (r=-0.544, p<0.001), children's attention problems (r=0.602, p<0.001), children's depressive symptoms (r=0.335, p=0.002), children's anxiety (r=0.306, p=0.004), children's behavioral problems (r=0.618, p<0.001), and parental anxiety (r=0.478, p<0.001), showed a significant correlation with parental stress. Children's behavioral problem (β=0.241, p=0.010), children's IQ (β=-0.472, p<0.001), and parental anxiety (β=0.426, p<0.001) were significantly related to the parental stress (Adjusted R²=0.619). Conclusions : Clinicians should pay attention to children's intelligence and behavioral problems and parental anxiety, which affect parental stress with children and adolescents with epilepsy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.303-313
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• 2020

Rice grain shape is one of the key components of grain yield and market value. An understanding of the genetic basis of the variation in grain shape could be used to improve grain shape. In this study, we developed a total of 265 F₂ individuals derived from a cross between japonica cultivars (Josaeng-jado and Langi) and used this population for quantitative trait locus (QLT) analysis. Correlation analysis was performed to identify relationships between grain traits (GL: grain length, GW: grain width, L/W: ratio of length to width, TGW: 1,000 grain weight). The grain shape was positively correlated with GL and TGW, and negatively correlated with GW. In QTL analysis associated with grain shape, one QTL for GL, qGL5, detected on chromosome 5, explained 20.3% of the phenotypic variation (PV), while two QTLs, qGW5 (PV=36.1) and qGW7 (PV=26.1), for GW were identified on chromosomes 5 and 7, respectively. Evaluation of the effects of each of the QTLs on the grain shape in the population showed a significant difference in the grain size in positive lines compared with the lines without the QTLs. According to the QTL combination of the allelic-types, the grain shape of the tested lines varied from semi-round type to long spindle-shaped type. The results of this study extend our knowledge about the genetic pool governing the diversity of grain shape in japonica cultivars and could be used to improve the grain shape of this species through marker-assisted selective breeding in Korea.

• Korean Journal of Poultry Science
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• v.40 no.2
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• pp.83-89
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• 2013

iNOS (Inducible nitric oxide synthase) and TLR-4 (Toll-like Receptor-4) play crucial roles in innate immunity of poultry. iNOS has been mapped to chicken chromosome 14 and implicated in a variety of chicken diseases. iNOS possesses potent antimicrobial activity, including the inhibition of microbes replication in vitro. TLR-4 is a pathogen associated molecular-pattern receptor for bacterial product, such as LPS (lipopolysaccharides) found in Gram negative bacteria, that triggers pro-inflammatory cytokine expression after engagement with ligands. In the previous studies, genetic analysis of iNOS and TLR-4 revealed the possible association of mutation in these genes with the intestinal microflora of cecum when infected with Salmonella spp. This study was aimed to augment previous findings, which show the association of iNOS (C14513T) and TLR-4 (G4409T) polymorphisms with economic traits in Korean Native Black (KNB), Rhode Island Red (RIR) and Cornish chickens. Investigation in the effect of SNPs on economic traits (layday, layw, layno, bw150, bw270, layw270) was conducted. iNOS (C14513T) had a significant effect on the average body weight at 270 days of age (p<0.05) in both KNB and RIR, whereas TLR-4 (G4409T) showed no significant correlation with all traits (p>0.05). The results obtained from using the candidate genes can be useful for the genetic improvement of body weight in both KNB and RIR breeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.233-238
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• 2006

This study was conducted to evaluate growth characteristics, yield and feed value of newly bred domestic silage corn hybrids compared to foreign imported corn hybrid. Days to silking were $78{\sim}86$ days and longer than that of P3394 (Control). Kwangpyeongok, Cheonganok, and Cheongsaok were resistant to lodging. Such trait of stay-green of Kwanganok, Kwangpyeongok, Cheonganok, Cheongsaok, and Suwon159 was not different from that of P3394. Duruok, Kwangpyeongok, and Suwon159 were more resistant to Bipolaris maydis (southern corn leaf blight) than P3394. All of the silage corn hybrids were resistant to Exserohilum turcicum (northern corn leaf blight) and Smut. Ear ratios to total dry matter (%) of Cheonganok was similar to P3394. Ear lengths of domestic hybrids were similar or longer than that of P3394. Dry matter yield of domestic hybrids except Suwon19 and Jangdaok were similar to that of P3394. Total digestible nutrient (TDN) yields, Duruok, Kwangpyeongok, Cheonganok, and Cheongsaok were similar to P3394, but Kwanganok, Suwon19, Jangdaok and Suwon159 were lower than P3394. Acid detergent fiber(ADF), Suwon19 was lowest among all hybrids, and all hybrids except Suwon19 had values ranging from 44.7 to 49.0%, similarly with P3394. Neutral detergent fiber (NDF) values of the hybrids were similar to that of P3394, and ranged from 68.1 to 72.8%, except for Duruok which was lowest. Relative feed values (RFV) of Duruok, Kwangpyeongok, Cheonganok, Jangdaok, and Suwon159 had values ranging from 71.0 to 75.7 and were not significantly different from P3394. ADF was significantly negatively correlated with number of days to silking, number of days to maturity, and fresh matter yield, but was significantly positively correlated with resistance to corn borer. RFV showed a significantly positive correlations with no. of days to maturity and fresh matter yield, but significantly negative correlation with resistance to European corn borer. Therefore, indices for evaluation of feed value as well as production were important to select corn hybrids for silage. It is concluded that domestic hybrids tested in this study have high feed value as well as high production similar to those of imported corn hybrid.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.49-57
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• 2001

Objectives : This study was designed to investigate the relationship between gastric emptying, psychopathology(especially anxiety and depression), and various factors that can mediate stress and response, such as coping style, social support and level of perceived stress. Methods : A total 30 patients who complained of the non-ulcer dyspepsia and did not have any abnormal finding on the gastroduodenal endoscopic examination, 24 hour ambulatory esophageal manometry and conventional gastroesophageal manometry were tested with gastric emptying that would be a functional examination of stomach. The correlations between the gastric emptying and psychological vaiable such as quantity of perceived stress, Symptom Checklist-90-Revision(SCL-90-R), Beck Depression Inventory(BDI), Spielberger Stait-Trait Anxiety Inventory(STAI), Ways of Coping Checklist and Interpersonal Support Evaluation List were evaluated. Results : 1) The mean and standard deviation of the time for half of the meal to empty(T50%) was $118.50{\pm}23.64$ minute which showed no gastric stasis in terms of gastric emptying test. 2) There were significant positive correlations between T50% and the state anxiety, T50% and thedepression. 3) There was no significant correlation between T50% and the quantity of perceived stress, T50% and mediating factors(coping style and social support). Conclusion : These results suggested that psychopathology, especially emotional components such as depression and anxiety, could affect on the current physiological functional gastric activity(gastric emptying), but quantity of perceive stress and mediating factors of stress and response such as coping style and social support could not affected on the functional gastric activity. These results showed that psychological interventions should considered in management of the patients with functional dyspepia.

• Sleep Medicine and Psychophysiology
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• v.4 no.1
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• pp.107-119
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• 1997

Objectives: The psychophysiologic response pattern between healthy subjects and patients with generalized anxiety disorder, and the relationship among anxiety rating scales and those patterns in patients were examined. Methods: Twenty-three patients with generalized anxiety disorder(AD) and 23 healthy subjects were evaluated by Hamilton Rating Scale for Anxiety(HRSA) and State-Trait Anxiety Inventory before baseline stressful tasks. Subjective Units of Distress were evaluated just before baseline period, immediately after stressful tasks, at the end of the entire procedure, and psychophysiologic measures, i.e., skin temperature(ST), electromyographic activity(EMG), heart rate(HR), electrodermal response(EDR) during baseline & rest and during two psychologically stressful tasks (mental arithmetic, TM; talk about a stressful event, TT) were also evaluated. Results: 1) AD group showed significantly higher EMG level during rest after stressful tasks and higher HR level during all period except TM compared to control group. 2) AD group showed lower change in the startle response(SR) of ST, in the SR & the recovery response(RR) of EMG during TM, and in the RR of EDR immediately after TM than control group. AD group showed that the RR of EDR was significantly lower than the SR during stressful tasks. 3) We found that there was significantly negative correlation between state anxiety and the RR of EDR after TT in AD group. We also found that there were significantly positive correlations between HRSA score and the SRs of EDR during stressful tasks, and between state anxiety and the SR of EDR during TT. Conclusion: Our results suggest that patients with generalized anxiety disorder show higher autonomic arousal than healthy subjects and decreased physiologic flexibility or reduced autonomic flexibility.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.495-503
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• 2010

Analyses were conducted to estimate the effect of quality grade on the carcass characteristics, physico-chemical and sensory traits of Longissimus dorsi in Hanwoo. A total of 42,113 carcasses were selected on the basis of five quality grades (grade $1^{++}$, $1^+$, 1, 2, and 3) and an additional 258 samples of Longissimus dorsi were used to evaluate the beef quality. The increase in quality grade from grade 3 to grade $1^{++}$ was significant (p<0.05) for carcass weight (from 338.7 kg to 387.2 kg), backfat thickness (from 7.45 mm to 12.23 mm) and marbling score (from 1.09 to 8.31). In contrast, significantly decreased levels of meat color, fat color, texture and maturity were apparent with increasing quality grade (p<0.05). Increasing quality grade was also correlated with significant increases (p<0.05) in crude fat contents (from 3.57% to 25.68%) and water holding capacity (from 52.41% to 58.03), and a decrease of the Warner-Bratzler shear force from 8.29 kg to 2.83 kg. The highest $L^*$ value (41.53) and highest cooking loss (22.11%) were observed with grade $1^{++}$ and 3 beef, respectively. There was no difference observed on $pH_{24}$ (5.53 to 5.66) among the quality grades, which were within the normal range. Sensory evaluation experiments revealed that quality grades were associated with significantly altered (all p<0.05) tenderness, juiciness, flavor, and overall acceptability. The crude fat contents showed significant correlation with juiciness (r=0.59), tenderness (r=0.71), flavor (r=0.55), and overall acceptability (r=0.69). The lower sensory trait scores were related to higher WBs. Grade $1^+$ Hanwoo beef had a significantly higher WBs and lower fat contents when compared to grade $1^{++}$ Hanwoo beef (p<0.05).