• Korean Aquaculture
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• v.14 no.1
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• pp.88-95
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• 2002

많은 척추동물의 성비는 1:1이며 암수는 각 세대에 거의 같은 수가 태어난다. 생식 행동도, 암컷만이 집단을 형성하는 대형 포유류 등을 제외하면, 암수 1:1로부터 차세대가 재생산 된다. 야생 집단에서는 같은 수의 암수를 전제로 대부분의 생태가 형성되어 있다고 생각되어 지기 때문에, 차세대의 유전적 영향도 암수에 의한 차는 일반적으로 없다. 그러나, 축산을 비롯한 산업 동물에서는 상품 가치, 생산 효율, 재생산 등에 암수의 성에 따른 큰 차이가 나타나는 경우가 있고, 암수 어느 한 쪽이 선택.사육되는 경우도 있다. 낙농의 암컷 소, 양계업의 암컷 병아리의 선택은 좋은 예라고 할 수 있다. 더욱이, 가축에서는 육종 목적으로 유전적으로 우량한 소수의 수컷으로 많은 암컷과 교배시키는 경우가 있고, 극단적으로 치우친 성비로 재생산을 행하는 경우도 있다. 이와 같이 산업동물에서는 성 제어의 유용성이 예상되어 기술 개발이 요구되고 있다. 산업 생산의 대부분은 자연 번식 집단으로부터의 어획물로 되어 있어, 이것들의 성 제어가 곤란하며 무의미하다. 그러나, 양식 대상종 및 종묘 방류를 행하는 재배어업에서는 그 기술 도임에 의한 효과가 기대된다. 인위적 재생산 기술이 확립되어 있는 어종에서는 양식, 증식을 불문하고 기술 개발과 도입여부를 적극적으로 검토하여야 한다. 여기서는, 재생산 기술이 확립되어, 양식 및 인공 부화 방류가 활성화된 연어.송어과 어류의 성 제어 기술 개발 상황과 실용화의 현상을 논하겠다.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.197-205
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• 1996

This study was conducted to examine the effect of sustained release recombinant bovine somatotropin(SR-rBST) with different dosage(0, 0.03mg/kg body weight/14 day, 0.06mg/kg body weight/14 day, 0.09mg/kg body weight/14 day) on the economical traits of the semen characteristics and sexual behaviors and blood chemical values with sixteen Holstein dairy young bulls in Dairy Cattle Improvement Center of National Livestock Co-operatives Federation. Sensual testings of collected semens of Holstein young bulls were not different among treatments (p>0.05). Ejaculated semen volumes of control, SR-rBST 0.03mg, 0.06mg and 0.09mg groups were 5.6ml, 5.6ml, 6.0ml and 6.7m, respectively, but the result of SR-rBST 0.09mg group significantly increased semen volume(P<0.05). In sperm concentration, SR-rBST 0.06mg and 0.09mg groups significantly increased the total number of sperms than the other groups(P<0.05). In otherwise, SR-rBST treatments did not affect on pH, osmotic pressure, anti forzen rate, abnormality and motility of collected semen during whole experimental period. Reaction time(RT), sexual aggressiveness(SA) and tactile stimulation(TS) were not different among treatments. The libido scores(LS) of control, 0.03mg, 0.06mg and 0.09mg groups were 68.0, 80.5, 73.9 and 80.8, respectively, and LS were significantly improved by SR-rBST administration(P<0.05). The effect of SR-rBST on scrotal circumference measurement that is important factor to determine the ability of semen production, was not different among treatments. These studies indicates that SR-rBST treatments favourably affect on semen quality and sexual libido in Holstein young bull.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.247-256
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• 1999

The present study was performed to improve the reproductive disturbance as well as the elimination of microbiological contamination for animals bred under conventional conditions followed by in vitro fertilization and embryo transfer techniques including embryo and sperm freezing, using a mouse strain(M. m. molossinus-tt＠Kist) showing the abnormal behavior disorder derived from Korean wild mice (Mus musculus molossinus). Moreover, hematological and serum biochemical analyses were also carried out to obtain the basic data of this mouse strain The results are summarized as follows: 1. In comparison with hematological data, the numbers of RBC and platelet of this mouse strain were appeared as the higher value those that of the same aged inbred strains such as BALB/c, DBA/2, C57BL/6 and C3H /Hen. However, no differences were found in values of WBC, Hb and Ht. Moreover, total cholesterol of this strain showed a low value but triglyceride, total protein and albumin values were similar as in inbred strains. 2. The average numbers of superovulated oocytes treated with 2.5/2.5 IU and 5.0/5.0 IU of PMSG/hCG were 11.6 and 12.7, respectively. The fertilization rates of 2.5/2.5 IU PMSG /hCG treatment(87.9%) was higher than 5.0/5.0 IU treatment(52.0%) (p＜0.05) and the developmental rate of 2 cell stage embryos were 외 so appeared as higher value 99.0% and 90.6%, respectively. 3. The rates of in vitro fertilization treated with frozen sperm(24.8%) was significantly lower than of that fresh sperm(87.9%), (p＜0.05). 4. The five, six and ten heads of offspring were obtained from frozen-thawed 2 cell embryos by in vitro fertilized, 2 cell embryos from in vitro fertilized by frozen-thawed spermatozoa. and 2 cell embryos by in vitro fertilization, respectively. These offspring developed the expected disease about 2 weeks after birth, which was confirmed that the disease character of this mutant mouse strain was reliably reproduced. 5. MHV(Mouse hepatitis virus) and Staphylococcus aureus were successfully eliminated from conventional animals by in vitro fertilization-embryo transfer and the use of SPF recipient animals.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.651-662
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• 2006

Phthalate esters that are used as plasticizers and also found at low levels in foods such as dairy products are often mentioned as suspected endocrine disrupters. The purpose of the present study is to elucidate whether perinatal exposure to di-n-butyl phthalate(DBP), diisononyl phthalate (DINP) and di-2-ethylhexyl adipate (DEHA) affects several aspects of reproductive function in rats especially sexual differentiation of the brain. To this end, the dams were provided with pulverized soy-free diet containing 20, 200, 2,000 and 10,000 ppm of DBP, 40, 400, 4,000 and 20,000 ppm of DINP, or 480, 2,400 and 12,000 ppm of DEHA from gestational day (GD) 15 to postnatal day (PDN) 21, the day of weaning, and serum sex steroid hormone, gonadotropin levels and sexual behaviors after maturation were assessed. At Postnatal week (PNW) 20-21, serum levels of sex steroids and gonadotropins in both male and female rats, as well as estrous cyclicity in females, were not changed by perinatal exposure to DBP, DINP and DEHA, indicating that these chemicals did not affect sexual differentiation of the brain controlling the endocrine system of hypothalamo-pituitary-gonadal (HPG) axis. On the other hand, inhibitory influences on sexual behaviors, especially on ejaculation in males and lordosis in females, were observed by perinatal exposure to these chemicals. These results suggest that these chemicals may act directly on discrete regions of the hypothalamus regulating sexual behaviors, but not regulating gonadotropin secretion, thereby affect sexual differentiation of the brain with a resultant decrease in sex-specific behaviors in adulthood.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.1067-1072
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• 2016

In this study, we determined the ecological characteristics of Strix aluco, which is designated as an endangered category II species. Towards this, we identified the actual home range of Strix aluco that breed in Korea, and collected the data necessary for protecting, preserving and managing owl populations. This study was conducted from April 14 to May 20 of 2016 during the breeding season of Strix aluco as part of the 4th National Ecosystem Survey and in accordance with the Natural Environment Conservation Act. We captured and subsequently released a female owl with a total length of 423.5mm and a weight of 550g in Kyungbuk area, succeeded in tracking it for the first time in Korea and secured 6 points of direct observation and satellite tracking observation. The distance from the nest to the farthest point was 93m. As a result of the analysis of habitat points within a100m-radius during breeding period, it was established that their habitat consists of 34.2% of non-irrigated land, 30.6% of mixed forest land, 10.5% of orchard, and 9.4% of natural grassland. These findings are consistent with the previous estimate of home range studies. Further research based on follow-up studies on males or other individuals is required to develop a stronger basis for protection and conservation of endangered wildlife class II owls.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.681-692
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• 2015

It is well documented that physiological and nutritional condition of wintering birds is strongly related to migration success to breeding sites, and also breeding success. However, how abiotic factors during winter affect the migration and breeding successes still remains unclear. Thus, this study developed a dynamic-state-dependent model for wintering life-history to identify the potential impact on the life-history, success to breeding site and breeding success of wintering birds, which are related to temperature fluctuation, interspecific competition and human disturbance at the wintering sites. To find the best-fit-model, we referred to the existing research data on wintering ecology of Red-crowned cranes (Grus japonensis) in Cheolwon, Korea, which is well documented as a long-term wintering study. Our model predicted that the higher temperature fluctuation and a higher rate of human disturbance are negatively related to migration success to breeding sites and their fitness, ultimately breeding success via changing of proportion in resource allocation (for e. g., lower energy compensation or higher level of stress accumulation). Particularly, the rate of body mass compensation after arrival at wintering sites may be accelerated when there are less temperature fluctuations and a lower rate of human disturbance. In addition, the rate of interspecific competition sharing the wintering foraging sites is negatively related to the rate of body mass compensation. Consequently, we discussed the conservation strategies of wintering birds based on the outcomes of the model.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.483-492
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• 2019

During the breeding season, both adults and immature Eurasian Oystercatchers (Haematopus ostralegus osculans) were observed to feed on prey, such as gastropods (Umbonium thomasi) and bivalves, at the tide water line around Yubu island in Korea. To determine differences in the foraging efficiency between the adult and immature birds, we recorded the feeding behavior using digiscoping with a telescope and a smartphone. We compared the pace, the prey search rate, the proportion of prey search techniques, the feeding success rate, the handling time, and the heads-up rate between the adult and immature birds. There were significant differences in the proportion of prey search techniques when gastropods were consumed and in the prey search rate and heads-up rate when bivalves were consumed but there were no significant differences in feeding success rates. Therefore, although the immature birds on Yubu Island were inferior to adults during the breeding season and they lacked the proficiency to locate prey, their overall foraging efficiency was similar to adults. This was considered to be due to the continuous eating of bivalves during the wintering season, which requires a high level of foraging efficiency.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.99-111
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• 2022

Akey factor in evolution is reproduction, which is also a major concern in medicine. Evolutionists have proposed many theories and hypotheses to explain the low fertility rates of modern industrial societies, which are contrary to maximization of biological fitness. Given that childbirth is the most significant factor affecting reproductive fitness, it is likely that a variety of psychological modules related to childbirth behavior and intention evolved over time. Several evolutionary psychological modules have been proposed in relation to reproduction, including sexual desire, status-seeking, a need for nurturing, and the desire for children. Previously adaptive psychological modules may now be expressed maladaptively due to the discrepancy between the Environment of Evolutionary Adaptedness (EEA) and the environment of modern industrial society. Several evolutionary ecological factors influence childbirth intention in modern society, including individual personality factors, childhood life history experiences, and socioecological factors throughout reproductive life. By focusing on mental, social, and ecological factors, this review examines several hypothetical models relating to evolutionary psychological factors and childbirth decisions in modern industrial society, as well as a possible explanation for the low birth rate.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.375-383
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• 2009

The aims of this study were wintering individuals, usage of foraging sites, potential food availability, daily activity and disturbance factors of White-naped Cranes Grus vipio on the wintering site, Han-river estuary, Goyang and Gimpo city, Korea. We want to provide basic data to conserve the cranes. Maxium population was identified 162 individuals at the middle of February in the river side and mud flat of this study area. Spring migration for breeding was started at the first week of March and finished for two weeks later. White-naped Cranes were used four feeding sites in winter; agricultural area in Hongdopyong, Yihwa-dong, Pyong-dong and Songpo-dong. Expected carrying capacity (ECC) was 334 days (121~909 days). White-naped Cranes departed from roosting site to feeding site at every morning for foraging. If they were disturbed by some factors at feeding sites, they moved to mud flat in the Han river to forage and take a rest. Daily activity was consisted of six category; feeding, alert, locomotion, preening, comfort, social and other behaviors. Feeding was the highest portion among behaviors in the wintering area. Feeding, alert, locomotion and preening in daily activities significantly differed among feeding sites. We watched total 348 times of disturbances in the wintering sites. Artificial disturbances were vehicles, humans, bicycles and motorcycles. Natural disturbances were noises, animals and others. Disturbances in all wintering sites were highest in Yihwa-dong (134 times) and followed by Hongdopyong (109 times), Songpo-dong (64 times) and then Pyong-dong (44 times). And artificial disturbances (228 times) were more than natural disturbances (120 times). Especially, vehicle was one of the most checked factor in the wintering area.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.6
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• pp.1309-1316
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• 2018

Cattle estrus detection system based on Internet of Things is designed and implemented by using Arduino pro-mini, gyroscope, acceleration sensor, bluetooth master and slave module. The implemented system measures cattle's moving and the measured data are transmitted to the computer connected to RX module by bluetooth TX module. They are plotted in 2-dimensional graph on the computer monitor and the number of transition at each sensor axis are calculated from the graph. The detected and gathered data from the system are analyzed by the proposed algorithm to decide which cows are in the estrus or not. The method to apply bluetooth scatternet is shown and the proposed system can be used to increase the success rate of artificial insemination in normal estrus by detecting the cow's behaviors such as the number of jumping. In this paper, the implemented cattle behavior detecting the system(TX module) are strapped on cattle's leg and it measures the cattle behaviors for determining where that a cattle is estrus or not by the proposed algorithm.