• Journal of Ecology and Environment
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• 제44권4호
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• pp.207-211
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• 2020

Adult land crabs generally live on land while their larvae live in the sea. In the case of Sesarma haematoche, female crabs migrate from land to sea to release the larvae at the high tide of syzygy night. Artificial structures along coastal areas are being obstacles for the migration of land crabs and causing synchronized roadkills on coastal roads during breeding migration. In this research, we compared the sex ratios of crab populations in coastal areas with coastal roads and uninhabited island areas with no road. The proportion of females in inland habitats with coastal roads was significantly smaller than island habitats. In particular, females are exposed to the risk of annually repeated roadkills, and the proportion of females decreases rapidly with their growth. If this tendency is general for land crab populations in the coastal areas with roads, significant road mortality of female land crabs during breeding migration can lead to severe population decline in coastal areas. Therefore, it is necessary to take an action to save land crabs crossing coastal roads.

• 생태와환경
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• 제47권3호
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• pp.194-201
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• 2014

번식 시작 전 어느 기간의 어떠한 기후요소가 고리도롱뇽의 번식이주 시기에 영향을 미치는 지를 파악하고자, 부산시 기장군 봉대산 일대에서 고리도롱뇽의 자연번식지와 인접한 대체번식지에서 2006년부터 2010년까지 5년의 번식기 동안 날짜에 따라 번식지에 출현한 개체들을 기록한 개체군 모니터링 자료와 조사지로부터 약 25 km 떨어진 기상대에서 획득한 기후정보 사이의 상관관계를 분석하였다. 연구결과, 번식 시작 전 약 1달 동안의 평균기온 및 평균최저기온은 대체번식지 내 암컷의 번식이주 시기에 영향을 미쳤으며, 번식 전 2~4달 동안의 겨울철 평균일교차와 평균강수량은 각각 자연번식지의 수컷과 자연번식지와 대체번식지의 암컷의 번식이주 시기에 영향을 미쳤다. 번식이주 시기와 기후 요소와의 관련성은 수컷보다 암컷에서, 자연번식지에서보다는 대체번식지에서 더 높았다. 이러한 연구결과는 년도에 걸친 단순한 평균온도의 상승보다는 겨울철을 포함하는 기간 동안의 평균강수량과 평균일교차의 변동이 유미양서류 번식이주 시기에 더 큰 영향을 미치는 것을 보여준다. 더불어 암컷의 번식이주 시기가 수컷에 비하여 기후요소에 보다 더 밀접하게 관련되며, 특별히 이주된 유미양서류의 개체군들에서 이주시기는 기후요소의 영향을 더 크게 받는다는 것을 보여준다.

• Journal of Ecology and Environment
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• 제30권2호
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• pp.121-126
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• 2007

We monitored gold-spotted pond frog (Rana chosenica) populations near the Korea National University of Education in Chungbuk, Korea, from 19 May to 8 August, 2006 to examine the spatial distribution of populations in local areas and to investigate patterns of migration of adult gold-spotted pond frogs from terrestrial hibernation sites to breeding sites, We captured individuals from the largest population using a drift fence with 22 pitfall traps surrounding the breeding site. A total of 22 individuals (19 males and 3 females) were captured between 23 May and 15 June. No peak in breeding migration was detected, but the onset of the breeding migration may correspond with increased humidity. Male body weights were negatively correlated with sampling dates. Seven of 22 individuals were captured at the 4th pitfall trap, which was placed between two culverts. The capture rate per pitfall trap was higher in traps close to the rice field banks (1.44, traps $1{\sim}9$) than in traps facing hilly land (0.33, traps $13{\sim}18$). Comparative data from the Korean frog (Rana coreana), a sympatric species in the study area, were also collected and compared with those of the gold-spotted pond frog.

• International Journal of Stem Cells
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• 제16권2호
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• pp.202-214
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• 2023

Background and Objectives: To investigate the role of exosomes from periodontal ligament cells (PDLCs) in bone marrow mesenchymal stem cell (BMSC) migration. Methods and Results: Human PDLCs were applied cyclic tension stretching. Exosomes were extracted from cultured PDLCs by ultracentrifugation, then characterized for their size, morphology and protein markers by NTA, TEM and western blotting. The process that PKH26-labeled exosomes taken up by BMSCs was assessed by confocal microscope. BMSC migration was examined by Transwell assay. Exosomes derived from PDLCs were identified. Cyclic tension stretch application on PDLCs can enhance the migration ability of BMSCs through exosomes. The exosomal miRNA expression profiles of unstretched and stretched PDLCs were tested by miRNA microarray. Four miRNAs (miR-4633-5p, miR-30c-5p, miR-371a-3p and let-7b-3p) were upregulated and six (miR-4689, miR-8485, miR-4655-3p, miR-4672, miR-3180-5p and miR-4476) were downregulated in the exosomes after stretching. Sixteen hub proteins were found in the miRNA-mRNA network. Gene Ontology and KEGG pathway analyses demonstrated that the target genes of differentially expressed exosomal miRNAs closely related to the PI3K pathway and vesicle transmission. Conclusions: The exosomes derived from cyclic tension-stretched PDLCs can promote the migration of BMSCs. Alternation of microRNA profiles provides a basis for further research on the regulatory function of the exosomal miRNAs of PDLCs during orthodontic tooth movement.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.489-494
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• 1998

This paper describes a design of graphical user interface for a simulated breeding tool with multifield. The term field is used here as a population of visualized individuals that are candidates of selection. Multi-field interface enables the user to breed his/her favorite phenotypes by selection independently in each field, and he/she can copy arbitrary individual into another field. As known on genetic algorithms, a small population likely leads to premature convergence trapped by a local optimum, and migration among plural populations is useful to escape from local optimum. The multi-field user interface provides easy implementation of migration and wider diversity. We show the usefulness of multi-field user interface through an example of a breeding system of 2D CG images.

• Journal of Ecology and Environment
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• 제30권4호
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• pp.287-292
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• 2007

We monitored a breeding population of the Asian toad (Bufo gargarizans), in the Wonheunge pond at Sannamdong, Chungju, from 5 March to 11 April, 2006 and 14 February to 31 March, 2007 to investigate their movement patterns, breeding population sizes, and physical characteristics. Terrestrial migration to the pond started on 5 March in 2006 and 14 February in 2007. We captured a total of 266 immigrating individuals (213 males, 53 females) in 2006 and 307 (222 males, 85 females) in 2007, and found 50 adults apparently killed by motor vehicles while migrating to the pond in 2007. Emigration from the pond to terrestrial sites started on 15 March 2006 and 5 March 2007. We captured a total of 245 emigrating toads (181 males, 65 females) in 2006 and 99 (92 males, 7 females) in 2007. An additional 10 emigrating adults were found dead on the road. During both the immigration and emigration periods, two peaks in capture frequency appeared for each sex in each breeding season. The immigration peaks corresponded with higher temperatures, while the emigration peaks corresponded with high humidity. Migrating Asian toads showed sexual size dimorphism and a male-biased sex ratio. Body weights and SVL (snout-vent length) of immigrating and emigrating individuals were negatively related with migration dates.

• 한국환경생태학회지
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• 제29권5호
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• pp.681-692
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• 2015

월동기간 동안 월동조류의 생리 및 영양학적 상태는 이후 번식지로의 이동성공과 번식성공에 영향을 줄 수 있음은 잘 알려져 있다. 그러나 환경적 요인들이 월동기간 동안 어떻게 몸 상태에 영향을 주어 장기적으로 이동과 번식에 영향을 주는지에 대해서는 아직까지 잘 알려져 있지 않다. 본 연구는 월동기간 동안 온도변화와 월동지에서의 인간 활동에 따른 방해가 개체수준에서의 월동하는 조류의 생활사에 미치는 영향과 번식지로의 이동 및 잠재적 번식 성공에 미치는 영향을 알아보기 위해 동적상태의존 월동 생활사 모델을 개발하였다. 모델에 사용된 지수는 월동개체군에 대한 연구가 잘 수행되어 있는 철원의 두루미 자료를 이용하였다. 모델은 온도 변화나 인간의 방해요인의 영향이 생존과 번식지로의 이동을 위한 에너지 축적 그리고 누적된 스트레스의 감소를 위한 자원 분배에 영향을 주는 것으로 예측하였다. 특히 월동지에 도래한 두루미 몸무게의 회복률은 기온변화가 적고 방해요인의 영향이 낮을수록 빨랐으며, 체내의 누적 스트레스는 기온변화가 크고 방해요인의 영향이 높을수록 회복속도가 낮을 것으로 예측되었다. 또한 월동지의 취식지를 공유하는 다른 종의 밀도가 높을수록 두루미의 몸무게 회복률이 낮은 것으로 예측되었다. 끝으로 모델의 예측된 결과를 통해 월동지에서의 월동조류 보전전략에 대해 고찰하였다.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.285-291
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• 2018

The impact of climate change on animals has been globally documented. Especially, migration of birds has been extensively monitored as migratory birds are susceptible to any changes occurring both on breeding grounds and on wintering grounds. However, in contrast to spring migration, the patterns and the factors for autumn migration have not been well documented. In this study, we investigated the relationship with climate condition and the first arrival dates (FADs) of bean geese (Anser fabalis) and white-fronted geese (A. albifrons), the representative group of wintering birds in South Korea, using the data collected by Korean Meteorological Association during 1995-2016. Average temperature of September in wintering grounds has increased, and the FADs of the geese have advanced over the 22 years. Even when the influence of autumn temperature was statistically controlled for, the FADs of the geese have significantly advanced. This suggests that warming has hastened the completion of breeding, which speeded up the arrival of the geese at the wintering grounds. In order to assess the effect of climate condition on the arrival of the wintering migratory birds such as the geese in more detail, extensive data collection over many sampling sites and with long-term monitoring is needed.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.183-191
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• 2008

To determine the age structure of a Hynobius leechii breeding population and analyze relationships between the order of entrance to breeding ponds and physical parameters and age, we studied a wild population of the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Korea from March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of females ranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm, respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-vent length (SVL), head length, and body mass of males were all positively correlated with their age, but female age did not show a significant relationship with any physical parameter. The tail depth, body mass, and condition factors (SVL/body mass $\times$ 100) of both males and females were negatively related with the order of entrance to the breeding pond. The head width and SVL of males were also negatively correlated with the order of entrance, but the SVL of females was positively related with the order of entrance. These results suggest that physical parameters are more important determinants of breeding migration patterns than age. We discuss which of two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explain the order of entrance to breeding ponds for male and female H. leechii.

• The Korean Journal of Ecology
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• 제24권4호
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• pp.219-222
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• 2001

The study was conducted to get the basic information for proper protection and management of black-faced spoonbill and their habitats in western coast of South Korea. The species was observed in 8 sites of western coast of South Korea in spring 2000. We confirmed breeding of this species at least 4 pairs in Seokdo island. This island is considered likely to be an imortant breeding site together with Yodo island, Hambakdo island and Yokdo island. Also, we observed breeding of herring gull in Seokdo island and small island nearby Boleumdo island for the first time in South Korea. Chilsando island, Cheonsuman bay and Gyeokyeolbiyeoldo island were considered as stopovers located on the Korean Peninsula route. The other sites were considered as summering sites of the black-faced spoonbill. Especially the birds were constantly observed from breeding season to postbreeding season in Seonduri and Yeochari of Ganghwado island. We have counted maximum 88 individuals gathered at Gaksiyeo in Seonduri and Yeochari on September 3, 2000. The species seemed to gather at these sites after breeding for migration to wintering ground in September. We also surveyed changes of the number of individuals as time of the ebb and flow on September 3 and 6, 2000, their time budgets were affected by the ebb and flow in these sites.