• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.272-274
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• 2003

A few studies have examined the hatching response of copepod diapause eggs to various factors (Ban and Minoda, 1991; Chen and Marcus, 1997). Marcus (1979) monitored the hatching of diapause eggs of Labidocera aestiva and suggested that diapause eggs of marine copepods undergo a refractory phase similar to other diapausing organisms. (omitted)

• Journal of Ecology and Environment
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• 제31권3호
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• pp.201-206
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• 2008

This study was conducted to determine clutch size and habitat usage of Kentish plovers (Charadrius alexandrinus) breeding on Sinja-do lslet in the Nakdong Estuary from 22 April to 12 July in 1995 and from 21 April to 20 June in 1996. The Kentish plover preferred grasslands and damp sands to dry dunes as nesting sites. The difference in hatching success among these microhabitats was attributed to high tides, which washed away many nests on damp sands, and strong winds, which frequently shifted the sand to bury eggs on dry dunes. The main mortality factor in grasslands was predation by magpies Pica pica. Each clutch contained one to four eggs, with a mode of three eggs. Hatching success was highest in two-egg clutches and lowest in one- and four-egg clutches. The mean interval for egg laying was 1.8 days between the first and second eggs and 2.1 days between the second and third eggs. The average incubation period was about 24.2 days.

• The Korean Journal of Ecology
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• 제25권6호
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• pp.365-369
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• 2002

We had 18 eggs artificially hatched in a mass breeding place of black-tailed gulls and examined the individual recognition between young siblings in a laboratory environment. The results of the experiment showed that the young gulls selectively responded to their siblings and non-siblings at an early stage after hatching. It was shown that they began to recognize the begging call among the voice signals of siblings and non-siblings 15-16 days after hatching, and the chirirah call 11-12 days after hatching. Also, more significant results were shown with the chirirah call than with the begging call. In an experiment of visual recognition between siblings and non-siblings, the young black-tailed gulls approached their siblings significantly 9-10 days after hatching. The recognition between young siblings in a mass breeding place provides an important evolutionary indicator in terms of their social behaviors.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 제16회 생물과학 심포지움 강연록
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• pp.68-73
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• 1995

Most female Great Tits lay one egg each day until the clutch is complete. However, some exceptions are found. “Pause day/s” most frequently occur after the 1st egg is laid. In general, egg-size increase with laying sequence, but there is year-to-year variation. The relationship between egg size and laying sequence is found more significantly in relatively larger clutches than in smaller ones. Great Tits tend to advance the hatching of their chicks by starting to incubate earlier in relation to clutch completion as the breeding season progresses. hatching asynchrony affects chick´s growth rate, but when the effect of laying date on hatching asynchrony is controlled, the effect of hatching asynchrony on growth rate is not found. These findings support the ´hurry-up´ hypothesis.

• 한국가축번식학회지
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• 제20권4호
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• pp.443-451
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• 1997

These studies were conducted to determine the sex of preimplantation Hanwoo embryos produced in vitro using polymerase chain reaction(PCR). Y chromosome specific and bovine speicific DNA primers were synthesized and tested for embryo sexing. Bovine IVF embryos were produced in TCM 199 and CR1aa medium, and classified by developmental stages on Day 7 to 9. The effects of developmental rates to bovine IVF blastocysts on sex ratio were also investigated using PCR methods. The results obtained in this study were as follows; 1. Developmental rates to blastocyst from IVM/IVF embryos in TCM 199 and CR1aa medium for 9 days were 23.5 and 30.2%, respectively, and there was significant difference between the media(P<0.05). 2. Male to female ratio of early, mid, expanded and hatching balstocyst produced on Day 7 were 0.7:1, 1.4:1, 2.2:1, and 2.5:1, respectively, and male embryos was significantly higher proportion in expanding and hatching blastocysts(P<0.01). 3. On Day 8, male to female ratio of early, mid, expanded and hatching blastocysts were 0.6:1, 1:1, 2.5:1, and 2.7:1, respectively. Both expanded and hatching blastocysts obtained a significantly higher proportion of males(P<0.01). 4. The male : female ratio of early, mid, expanded and hatching blastocyst produced on Day 9 was 0.6:1, 0.8:1, 1:1, and 2.2:1, respectively. Hatching blastocysts had a significantly higher ratio of males(P<0.01). The developmental rate of IVM/IVF embryos to blastocyst for 9 day culture was higher in CR1aa than that in TCM 199 medium. For the sex ratio by developmental stages of IVF embryos, male ratio was higher in expanded blastocyst but female in early blastocysts.

• Environmental Analysis Health and Toxicology
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• 제22권1호
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• pp.83-90
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• 2007

This study was investigated the effort of growth and gonadal development in olive flounder, Paralichthys olivaceus exposed to PCBs Effluent Allowance Concentration, 3.0 ppb in Korea. Total length, body weight and weight gam of fish were no significant differences between two treatments (control: T.L.-110.0 mm, T.W.-9.61 g: treatment: T.L.-112.8 mm, T.W.-9.68 g), however, weight gain of fish unexposed to PCBs wat observed to increase gradually from 100 days after hatching (30 days after treatment). In the indifferentiated gonad to the juvenile stage, the differentiation of the ovary occured at 60 days after hatching (20 days after treatment) and that of the testis occured at 70 days after hatching (30 days after treatment) in two groups. In the ovary, the oogonia and ovarian lamellar appeared 130 days after hatching (50 days after treatment). The spermatogonia and resticular lobule of the testis were observed at 130 days after hatching (50 days after treatment). Testicular cyst appeared 140 days after hatching (60 days After treatment). There was no difference on the development of ovary and testis. There was no obvious difference of sex ratios. Therefore, These results considerate that PCBs have any effect for growth and gonadal development, but a little act for early growth in olive flounder.

• 한국응용곤충학회지
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• 제45권3호
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• pp.381-383
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• 2006

멸종위기종인 꼬마잠자리의 부화율을 5개의 온도조건($10,\;15,\;20,\;25,\;30^{\circ}C$)에서 조사하였다. 꼬마잠자리의 알은 2006년 7월 경상북도 문경시 일대의 한 작은 습지에 서식하는 암컷 성충으로부터 채취하였다. 부화율은 100일 동안 부화한 유충의 수로부터 구하였다. 꼬마잠자리의 알은 20, 25 및 $30^{\circ}C$의 온도조건에서 각각 83, 89 및 76%가 부화하였으며, $10^{\circ}C$와 $15^{\circ}C$에서는 실험기간동안 부화하지 않았다. 꼬마잠자리 알의 부화 임계온도는 $14.3^{\circ}C$로 추정되었으며, 다른 온대성 잠자리류보다 상대적으로 높았다.

• 한국가금학회지
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• 제27권3호
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• pp.181-187
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• 2000

This work was designed to investigate the performances of broiler breeder hens upon the addition were vitamin and mineral supplements in feeds. Animals were divided into for feed groups such as control, T$_1$,T$_2$and T$_3$, and each treatment has four replications. All broiler breeder hens were housed individually, and were fed with identical iso-metaboilic energy and iso-protein, except for vitamins and minerals. Different sources and levels of vitamins and minerals were added to the basic feeds according to the treatments. At the end of the experiments, general laying rate(hen days), average egg weight, hatching egg laying rate(Hen day) every day. Hatching egg weight, sterility, embryo mortality, hatching rate and chick weight were examined. Although, early laying rate in all treatment groups were reduced during cold term management, general egg laying rate was increased only T$_3$group which was contanining vitamin C. However, similar results were obtained in the rates of general and hatching egg laying. General egg laying rate were somewhat higher of Control, T$_2$and T$_3$ groups than that of T$_1$group. In addition, the laying rates of general and hatching eggs slightly improved in the T$_3$group rather than those of Control group. Egg weight was reduced with the increasing of laying rate, showing the highest in the T$_3$group. The laying rate showed significantly lower value than those of any other groups. Egg weight was about 65g in T$_3$group. The results of hatching performance for production ability of Broiler breeder hens were fed experimental diet, although the rates of non-hatched and hatched eggs increased in order of Control, T$_1$T$_2$and T$_3$groups. However, the rate of embryo mortality was declined in order Control, T$_1$T$_2$and T$_3$groups.

• 한국가금학회지
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• 제13권2호
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• pp.187-195
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• 1986

본 연구는 상용종계 모계통으로 이용되고 있는 White Plymouth Rock종에서 부화시간에 따른 체중과 체척치의 차이를 구명하기 위하여 실시하였다. 종웅계 60수와 종빈계 300수를 교배하여 생산된 종란을 부화하여 발생된 초생추중 "C"계통 551수와 "D"계통 424수등 총 975수를 육성하여 조사한 성적과 부화시간을 479시간부터 3시간 간격으로 521시간까지 14회 조사하여 얻은 자료에 근거하여 실시하였다. 본 연구에서 얻은 결과를 요약하면 다음과 같다. 1. 부화시간별 체중 및 체척치 : 4, 6주 및 8주령 체중, 흉골장 및 정강이 길이의 평균치는 부화시간이 경과함에 따라 낮아지는 경향을 뚜렷이 볼 수 있었다. 수탉에 있어 부화시간의 효과는 대부분의 형질에 대하여 고도의 통계적인 유의성(P〈.01)을 보였고, 6주 및 8주령 흉골장은 유의차가 없었으나 부화시간이 경과함에 따라서 흉골장이 뚜렷하게 짧아지는 경향을 보였다. 암탉에 있어 부화시간의 효과는 주령별 모든 형질에 대하여 통계적 유의성이 있었고, 수탉에서와 마찬가지로 부화시간이 증가할수록 각 주령별 체중이 현저하게 작아지는 경향을 나타냈다. 2. 계통별 체중 및 체척치 : 계통별 부화시간에 따른 평균능력 중 부화시간은 "D"계통이 "C"계통보다 수탉이 7.4시간, 암탉은 7.2시간이 더 길었으며, 산육능력에서는 "C" r계통이 모든 형질에서 더 우수하였다.

• Clinical and Experimental Reproductive Medicine
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• 제26권3호
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• pp.345-353
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• 1999

In the studies on the hatching mechanisms in mammals, many investigators focused on the embryonic intrinsic factor(s) in in vitro culture, but the uterine environment as the extrinsic factor(s) is thought to play an important role in hatching mechanism. Therefore, to evaluate the effect of uterine environment on the hatching event in vivo, the immature(GV) and ovulated(MII) oocytes, and the late 2-cell embryos of mouse were transferred to pseudopregnant foster mother's uterus during peri-implantation period. So it was verified whether there would happen hatching by only uterine environment independently on embryonic stage. The ultrastructural changes of the zona surface of transferred group were compared with those 01 in vivo and vitro group by SEM. 36 hrs after transfer, the immature and ovulated oocytes almost degenerated, and the late 2-cell embryos developed to various embryonic stages. However, the embryos which didn't develop to blastula stage did not hatch. The ultrastructural network of ZP in transferred group seemed to be smoothed uniformly, which was different from in vitro group. In conclusion, it is suggested that the uterine environment during peri-implantation period enhances the embryo hatching by provoking the structural change of ZP.