• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.111-111
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• 2003

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.

• Korean Journal of Veterinary Research
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• v.12 no.2
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• pp.165-175
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• 1972

The frequency distribution and morphological characteristics of tissue mast cells in the various tissues of normal domestic animals (bovine, swine, dog and chicken) and systematically infected (Hog cholera, Canine distemper and Newcastle disease) animals were studied. The results were as follows: 1 In cattle, density of mast cells was higher in foetus (bovine) and young animals than in adults Differences in frequency distribution among individual animals were also observed. 2. In chicken, the highest number of mast cells was found in age group of 15 to 40 days, the moderate number in age group of one to 10 days, and the lowest number in age group of 40 days or older. 3. The morphologically, mast cells were usually round, ovoid, spindle, oval and irregular, and particularly in ovary of bovine, it was usually round and ovoid forms. 4. The largest numbers of mast cells were shown in ovary of bovine, intestine of swine and dog, and proventriculum of chicken. 5. In the systemic infections, the number of mart cells usually tends to increase.

• Korean Journal of Veterinary Research
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• v.14 no.1
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• pp.77-90
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• 1974

Hemolytic reaction of normal fresh chicken serum on sheep erythrocytes was studied and the following experimental results were obtained and summarized. 1. Chicken sera, 258 (78%) out of 344 samples showed hemolytic activity on sheep erythrocytes. 2. Distribution of a different hemolytic titer of chicken sera was not dependent to sex and age difference of test chicken. 3. Hemolytic activity of serum component obtained from normal fresh chicken was heat inactivated at $56^{\circ}C$. 30 minutes heating. 4. The most enhanced hemolytic activity of chicken serum on sheep erythrocytes was observed at the incubation temperature of $46^{\circ}C$. 5. The most effective pH for the hemolytic reaction of chicken serum on sheep erythrocytes was observed at 7.0, and pH 6.0 or 8.5 resulted less or no hemolysis. 6. Hemolytic reaction of chicken serum and sheep erythrocytes required Mg⧻ and Ca⧻ ions as, co-factor, and the former was required more compared to the latter. 7. Hemolytic activity of chicken serum was observed in ChC 2, 4 fraction but not in ChC 1, 3, ChC 3, 4, ChC 1, 2, 4 and ChC 1, 2, 3 fractions. 8. In electron micrography, morphological changes of sheep erythrocyte membrane by normal chicken serum was similar to that of immune hemolysis: that was, the hemolytic hole was circular and it was surrounded with a white ring. 9. Electron micrography of morphological changes on sheep erythrocyte membrane indicated that the size of hemolytic hole and white ring were functional to the chicken serum concentration used and reaction time.

• Korea-Australia Rheology Journal
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• v.19 no.2
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• pp.89-95
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• 2007

The flow characteristics of chicken blood in a micro-tube with a $100{\mu}m$ diameter are investigated using a micro-Particle Image Velocimetry (PIV) technique. Chicken blood with 40% hematocrit is supplied into the micro-tube using a syringe pump. For comparison, the same experiments are repeated for human blood with 40% hematocrit. Chicken blood flow has a cell-free layer near the tube wall, and this layer's thickness increases with the increased flow speed due to radial migration. As a hemorheological feature, the aggregation index of chicken blood is about 50% less than that of human blood. Therefore, the non-Newtonian fluid features of chicken blood are not very remarkable compared with those of human blood. As the flow rate increases, the blunt velocity profile in the central region of the micro-tube sharpens, and the parabolicshaped shear stress distribution becomes to have a linear profile. The viscosity of both blood samples in a low shear rate condition is overestimated, while the viscosity in a high shear rate range is underestimated due to radial migration and the presence of a cell-depleted layer.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.45-48
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• 2012

The imidazole dipeptide carnosine and its methylated anserine analogues are the major histidine containing dipeptides in vertebrate tissue, especially in skeletal muscle, the heart, and the central nervous system. In this study, the carnosine and anserine content in chicken from different parts and of differing ages was determined and their physiological activities were compared. Anserine was more dominant than carnosine in these tissues and both of them significantly decreased with aging in all parts of chicken muscles. Chicken breast muscle showed the highest content of carnosine and anserine than drumstick and wing. Advanced glycated end-product (AGE) formation was inhibited up to 60% by the extract from 20 wk chicken breast and decreased with aging (90 wk). Anti-oxidation activity was also significantly reduced from 61.2% to 52.9% with aging. As results, anti-glycation and anti-oxidation activity of carnosine and anserine extract from chicken muscle increased proportionally to the amount of those peptides in the muscle, while these decreased with the aging process.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.656-661
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• 2023

The aims of this study were to optimize the preparation of low-molecular-weight collagen using a proteolytic enzyme (alcalase) derived from the feet of Korean native chickens, and to characterize the process of collagen hydrolysis. Foreign bodies from chicken feet were removed using ultrasonication at 28 kHz with 1.36 kW for more than 25 min. The hydrolytic pattern and molecular weight distribution of enzyme-treated collagen from chicken feet were analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-performance liquid chromatography, respectively. Ideally, chicken feet should be treated at 100℃ for 8 h to obtain a high collagen content using hot water extraction. The collagen content of the chicken foot extract was 13.9 g/100 g, and the proportion of low-molecular-weight collagen increased with increasing proteolytic enzyme concentration and reaction time. When treated with 1% alcalase, the average molecular weight of collagen decreased rapidly to 4,929 Da within 5 h and thereafter decreased at a slower rate, reaching 4,916 Da after 7 h. Size exclusion chromatography revealed that low-molecular-weight collagen peptides of approximately 1,000-5,000 Da were obtained after hydrolysis with 1% alcalase for 1 h.

• Asian Journal of Business Environment
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• v.14 no.2
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• pp.31-40
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• 2024

Purpose: This study aims to explore the factors affecting the willingness to pay for chicken delivery services targeting college students. The results of this study provide insights for improving food delivery market services and developing effective marketing strategies. Research design, data and methodology: A survey employing a questionnaire was administered to students at Chungbuk National University over a 10-day period from May 15 to May 24, 2023. Out of 232 distributed surveys, 218 were considered suitable for analysis. Binomial logistic regression analysis was conducted with the willingness to pay for delivery fees contingent on chicken price, serving as the dependent variable. Results: The main findings are following. First, as the price of chicken increases, the percentage of individuals willing to pay more than 2,000 won for delivery services decreases. Second, regardless of chicken price, males exhibit a lower tendency to bear higher delivery service fees compared to females. Lastly, those who lack awareness of their recent delivery fees or have previously paid charges exceeding 3,000 won demonstrate a greater propensity to pay higher delivery service fees compared to those who have paid fees below 3,000 won. Conclusions: It is essential for chicken sellers to identify key customer segments such as single-person households, and offer pricing and services tailored to their needs and preferences.

• Korean Journal of Poultry Science
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• v.42 no.4
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• pp.275-283
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• 2015

A consumer survey was conducted for the subject of a total of 503 housewives in Korea, with the questionnaires on the quality attributes for Korean native chicken. The responding results collected were used for the importance-performance analysis of the quality attributes involved in production, processing, distribution, and consumption of Korean native chicken. The quality attributes with both relatively high importance and performance ("keep up the good work") were chicken origin, shelf life, freshness, and safety issues, while those with high importance but low performance ("concentrate here") were chicken breed certification and refrigerated/ frozen state. Respondents were also interested in lean meat and protein content of the chicken meat. In the aspect of eating quality attributes, chewiness was the most important one. The survey shows tenderer, chewier, and more flavorful chicken meat will be preferred and a new chicken breed with those eating quality attributes needs to be developed.

• Journal of the FoodService Safety
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• v.3 no.2
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• pp.49-58
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• 2022

The objectives of this study were to investigate the behavior characteristics of pathogenic E. coli, Salmonella Typhimurium, Campylobacter jejuni, and Listeria monocytogenes in various kinds of meat (beef, chicken, and pork) and to compare their risk using FDA-iRISK. The growth of S. Typhimurium in chicken and pathogenic E. coli in pork and beef was well supported and posed a high risk. A similar trend was observed in the risk comparison results using the iRISK. When comparing total disability adjusted life years (DALY) per year based on the kinds of meat, chicken was the highest (88.2), followed by pork (58.5) and beef for "yukhoe" (18.8). When comparing scenarios grouped by bacteria, The highest total DALYs per year was observed with pathogenic E. coli (121), followed by S. Typhimurium (44.8) and L. monocytogenes (1.67E-³). These results indicate that the risk of combining meat and foodborne pathogens varies under the same distribution environment. Thus, strict management and supervision are required to store and deliver raw meat to prevent cross-contamination among the raw meats at the processing plant and retail market.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.530-536
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• 2010

Cdc25B is a mitotic regulator that might act as a starter phosphatase to initiate the positive feedback loop at the entry into mitotic (M) phase. In the present study, distribution of Cdc25B mRNA in duodenal mucosa of the chicken was demonstrated by means of in situ hybridization histochemistry (ISHH) using sense and antisense digoxigenin (DIG)-labeled RNA probes. The results showed that there were many labeled cells distributing in the duodenal mucosa of the adult chicken. Of these labeled cells, 81.60${\pm}$9.63% of Cdc25B mRNA positive cells was distributed in the basilar part and mid-portion of the intestinal gland and 36.21${\pm}$8.81% in the middle and basilar portion of villi of the small intestine of the chicken, respectively. Most of these labeled cells were positive in the regions of the stem cell and proliferation. The signals of ISHH decreased from basilar to upper part in the crypt of Lieberkuhn and weakened in the inferior villi of the duodenum. Moreover, the positive signals were both in the cytoplasm and cell nucleus. However, the labeled cells were negative in both the lamina muscularis mucosae and muscular layer. The results of ISHH suggested the existence of Cdc25B mRNA and vigorous proliferation activities in the duodenal mucosa of adult chicken, replenishing the cells which had sloughed off from the superior part of the villus. Our results provide some molecular evidence for a regular pattern of avian intestinal epitheliosis and functional partition and provide an approach to further study of the locations of Cdc25B in the chicken.