• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.117-122
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• 2019

The objective of this study was to establish an in vitro culture system for ovarian preantral follicles of B6D2F1. First, we optimized the in vitro preantral-follicle culture by culture duration, follicle stimulating hormone (FSH) type, and activin A concentration. Duration of in vitro culture for 9, 11, and 13 days was sufficient for the normal development of preantral follicles to antral follicles. Formation of cumulus cell-oocyte complex (COC) was induced by treatment with human chorionic gonadotropin (hCG; 2.5 IU/mL) and epidermal growth factor (EGF; 5 ng/mL). In addition, metaphase II (MII) oocytes formed during this in vitro culture of preantral follicles. In vitro preantralfollicle culture for 9 days showed higher rates of growth and maturation, thus yielding a greater number of antral follicles, and there were significant differences (p < 0.05) in the number of MII oocytes (that formed from these preantral follicles via differentiation) between the 9-day culture and 11-day or 13-day culture. The follicles cultured for 9 days contained a tightly packed well-defined COC, whereas in follicles cultured for 11 days, the COC was not well defined (spreading was observed in the culture dish); the follicles cultured for 13 days disintegrated and released the oocyte. Second, we compared the growth of the preantral follicles in vitro in the presence of various FSH types. There were no significant differences in the growth and maturation rates and in differentiation into MII oocytes during in vitro culture between preantral follicles supplemented with FSH from Merck and those supplemented with FSH from Sigma. To increase the efficiency of MII oocyte formation, the preantral follicles were cultured at different activin A concentrations (0 to 200 ng/mL). The control follicles, which were not treated with activin A, showed the highest rate of differentiation into antral follicles and into MII oocytes among all the groups (0 to 200 ng/mL). Therefore, activin A (50 to 200 ng/mL) had a negative effect on oocyte maturation. Thus, in this study, we propose an in vitro system of preantral-follicle culture that can serve as a therapeutic strategy for fertility preservation of human oocytes for assisted reproductive medicine, for conservation of endangered species, and for creation of superior breeds.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1638-1652
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• 2000

Prolific females require better nutrition and feeding practice because of larger litter size and the substantial decline in body fat. Life-time pig output will be compromised if body protein and fat are not properly managed. First litter females are especially vulnerable because they can loose ${\geq}15%$ of whole-body protein. Conservation of body protein mass during first lactation minimizes wean to estrus interval and increases second litter size (up to 1.2 pigs). The ability to influence litter-size by amino acid nutrition is a new dimension in our understanding. A P2 fat depth below 12 mm at farrow and below 10 mm at wean compromised wean to estrus interval (>2 d) and next litter size (0.5 to 1.5 pigs) in sows. It is now clear that a 'modest' excess of feed during the first 72 h of pregnancy decreases embryo viability so that the potential for an increased litter size at birth is not realized. The capacity for milk production by prolific young sows is 25% higher than the standard used previously (NRC, 1988). First litter females averaged 9.82 kg milk/d for a 21 d lactation. Second and third litter counterparts averaged 10.35 kg/d. Milk production was 95% of peak by 10 d of lactation and sows were in greatest negative energy and lysine balance during the first 6 d. Nearly 45% of the total loss in body protein occurred within the first 6 d, but this could reduced to 30-35% by using a more aggressive feeding strategy after parturition. There appear to be 2 phases in lactation for lysine need (d 2-12 vs 12-21). Feeding to the higher level alleviates the second litter size decline. The lysine requirement for lactation can be predicted with accuracy, but we are not able to predict the second limiting amino acid. Mammary uptake of valine relative to lysine and recent work with practical diets suggest that the recent NRC (1998) pattern is realistic and that threonine and valine could be co-limiting for corn-soy diets for prolific sows nursing 10-11 pigs. Empirical studies are needed to refine the ideal pattern so that synthetic lysine can be used with more confidence. Milk fat output for the elite sow is extraordinary and poses an unnecessarily high energetic cost. Methods that reduce mammary fat synthesis will benefit the sow and may enhance piglet growth.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.122-131
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• 2020

Marine Spatial Planning is an emerging strategy that promoting sustainable development at coastal and marine areas based on the concept of ecosystem services. Regarding its methodology, usage rate of resources and its impact should be considered in the process of spatial planning. Particularly, considering the rapid increase of coastal tourism, visitation pattern is required to be identified across coastal areas. However, actions to quantify visitation pattern have been limited due to its required high cost and labor for conducting extensive field-study. In this regard, this study aimed to pose the usage of social big data in Marine Spatial Planning to identify spatial visitation density and critical management zone throughout coastal areas. We suggested the usage of GPS information from Flickr and Twitter, and evaluated the critical management zone by applying spatial statistics and density analysis. This study's results clearly showed the coastal areas having relatively high visitors in the southern sea of South Korea. Applied Flickr and Twitter information showed high correlation with field data, when proxy excluding over-estimation was applied and appropriate grid-scale was identified in assessment approach. Overall, this study offers insights to use social big data in Marine Spatial Planning for reflecting size and usage rate of coastal tourism, which can be used to designate conservation area and critical zones forintensive management to promote constant supply of cultural services.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.4
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• pp.106-118
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• 2002

In recent years, synthetic and systematic management with conservation-oriented strategy for Baekdu-daegan, which is the greatest chine as well as the major ecological axis of the Korean Peninsula, is being required to cope adequately with the various kinds of developmental urge. For this, spatially definite zoning for the managerial area on Baekdu-daegan has to be completed first. This study is to take into consideration the traditional concepts of stream and watershed as well as the actual disturbance on Daegan area, and to propose the process for reasonably establishing the managerial boundary adjacent to the Ridges. The case site with topographically diverse characteristics was selected, and the analyses on watershed, road network and land use were carried out using the digital maps and Landsat TM images. Based on these analyses results, the managerial boundaries as alternatives from the Ridges were produced by watershed expansion process, and used for tracing the changes of road occupancy rate and the areal ratio of various land use types to the relevant watersheds to search out the adequate managerial boundary. The results show that watershed expansion process could be effective tool for establishing the managerial boundary, and the fourth expanded watershed would be included for the adequate managerial boundary of the case site.

• Journal of the Korean Geographical Society
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• v.49 no.6
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• pp.849-864
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• 2014

The objective of this paper is to investigate both the processes of regional policy and their determinants of the International Garden Exposition Suncheon Bay Korea 2013(IGEXPO 2013). IGEXPO 2013 was held in Suncheon from April to October 2013, and almost 440 million tourists visited to IGEXPO 2013. The processes of regional policy of the IGEXPO initiative were divided into four stages; the first stage from 1992 to 2002 was a beginning of conservation movement for Suncheon Bay; the second stage from 2003 to 2007 was a constructing of natural ecological park of Suncheon Bay; the third stage from 2008 to 2010 was a beginning of IGEXPO initiative and a confirming of the IGEXPO 2013; the four stage from 2011 to 2013 was a preparing and holding of IGEXPO 2013. The major determinants related to regional policy development process of IGEXPO initiative are the population n movement for Suncheon Bay, the rergional development strategy for central city in Gwangyang Bay area, the leadership for continuity of regional policy oriented to environmental and ecological city, and the cooperation and competition relationalship with neighboring city, in particular Yeosu city and 2012Yeosu EXPO planning. IGEXPO 2013 has been evaluated as having some performances such as the enhancement of city image, establishment of city park as a public goods, and formation of community leadership promoting continuous urban policy for environmental & ecological city.

• Journal of Wetlands Research
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• v.9 no.2
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• pp.21-31
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• 2007

Estuarine wetland, where freshwater meets saltwater, is a transitional ecosystem that is valuable ecologically for a variety of reasons, such as feeding and breeding sites for birds, fish, and wildlife. However, research on the spatial distribution and temporal dynamics of estuarine wetlands in Korea is rare. As a fundamental basis for wetland conservation, this study quantified the wetlands in three major estuaries, and evaluated the temporal dynamics of the wetlands since the 1910s. In particular, this study classified the wetland types into mud flat, sand, and emergent-plant types, and estimated the change of each wetland type, using topographic maps produced in the 1910s, 1970s, and 2000s. The wetlands in both the Han and Youngsan River estuaries have declined since the 1910s, but the rate of wetland decline was relatively low before the 1970s, compared to that since the 1970s. The impact of human activities, such as the Youngsan Watershed Comprehensive Development Project and the construction of estuary barrages, has disrupted the estuary cycles and destroyed huge amounts of wetland in the Youngsan estuary. By contrast, estuarine wetlands have been preserved in the small Gahwa estuary, and provide a variety of habitats for plants and wildlife. A special management strategy for wetlands should be established as soon as possible.

• Journal of the Mineralogical Society of Korea
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• v.15 no.2
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• pp.132-139
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• 2002

The physical properties of Uhangri sedimentary rocks were investigated to provide the conservation strategy of Dinosaur trace fossil in the Haenam. The porosity, void ratio, dry density, water content, and degree of saturation were calculated according to the proper laboratory experiments for 9 sedimentary specimens. The flexural strength (or modulus of rupture) and thermal expansion coefficient were measured using the universal testing machine and dilatometer, respectively. The Uhangri sedimentary rocks have very low porosity, void ratio, and water content. The flexural strength of shales are 24.16~42.84, and those of sandstones are 16.34~ $43.52N/mm^2$, which are much weaker than common sedimentary rocks. The very low flexural strength of sedimentary rocks despite very low porosity, is ascribed to fine fissures in the rocks. The thermal expansion coefficient of rocks were $14.7~21.3\Times10^{-6 }$, which are 2~2.5 times as high as alumina and about 10 times as high as talc. As the content of chert in the sandstone increases, the porosity, void ratio, and water content increase, while the dry density and degree of saturation decrease. The chert-bearing sandstone have higher porosity and thermal expansion coefficient, and lower flexural strength compared to those free of chert.

• Korean Journal of Environmental Biology
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• v.30 no.2
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• pp.107-120
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• 2012

This study was carried out to illiminate the diversity of vascular plants by making list of rheophyte and hydorphyte plants at Yugu stream. This study was conducted from Aug., 2009 to Sept. 2010 at 7 points. Based on the voucher specimens, vascular plants from investigated areas were 88 families 229 genera 290 species 3 subspecies 30 varieties 5 forms, totally 328 taxa. Korean endemic plants were 3 species such as Forsythia koreana (Rehder) Nakai (planted) and Paulownia coreana Uyeki (planted), and Weigela subsessilis (Nakai) L.H. Bailey. The rare and endangered plants were designated by Korea Forest Service were 4 taxa, such as Penthorum chinense Pursh, Acorus calamus L., Lilium callosum Siebold & Zucc. and Iris ensata var. spontanea (Makino) Nakai. Floristic special plants were totally 26 taxa, which were grade V of 2 taxa, grade IV of 2 taxa and grade III of 9 taxa. Naturalized plants were 27 taxa, that was 8.3% of whole discovered vascular plants in this area. Even naturalized plants has not influence on the vegetation of Yugu stream. Since village was composed along the stream and the roads and banks were linked, naturalized plants were flowed continuously into this region. So, strategy of the conservation for this region should be designed. Based on flora, 3 types of group were discriminated such as main stream type (4 points), branch stream type (2 points) and reservior type (1 point). Each group has difference in composition of plants.

• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.143-151
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• 2016

Shoreline armoring is a globally used engineering strategy to prevent shoreline erosion along stream, lake and reservoir coastlines. Armoring alters the land-water interface and has the potential to affect shoreline vegetation by changing nearshore geomorphology, hydrology, sediment composition and water quality. We quantified the effects of the artificial disturbances and alternation of the land-water interface on the community structure and distribution of shoreline vegetation in a large reservoir, Uiam Reservoir, Korea. More than 60% of shorelines were disturbed by armoring with retaining wall of concrete block, riprap and gabion in the Uiam Reservoir. The results of detrended correspondence analysis showed that the vegetation structures of the shoreline modified by armoring changed from hydrophyte-dominated to hygrophyte-dominated ecosystems. The shoreline armoring caused the disruption of gradual continuity in the water-land interface and the biological invasion by alien plants. The changes in distribution area of shoreline vegetation showed that the area of hydrophytic vegetation decreased and that of hygrophytic vegetation increased from 2010 to 2013. In conclusion, the human disturbance such as armoring, road construction, recreation etc. could lead to terrestrialization, the loss of transverse continuity and biological invasion in the shoreline vegetation of the Reservoir Uiam. Our findings suggest that redesigning or removing shoreline armoring structures may benefit nearshore hydrophytic vegetation for the conservation of novel shoreline ecosystems.

• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.81-89
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• 1999

To propose basic information for natural resource management and conservation strategy of Schisan-dra nigra Maxim., its habitat environment and vegetation structure of forest communities growing the species was investigated. Fourteen plots (each plot size 400 $m^2$) were set up at the distributed area of Cheju island, southern part of Korea. S. nigra is the economic useful species that scatteringly grows at 850~920 m in the western part, at 660~710 m in the northern part and at 750~1,250 m in the southern part of Mt. Halla. The community of S. nigra in Mt. Halla is the mixed secondary forest of pine and broad leaved trees that are mainly composed of Pinus densif1ora, Quercus serrata, Styrax japonica, Lin-dera erythrocarpa and Carpinus laxiflora. The density in a main distribution sector of S. nigra appears in the range of 3~39 individuals per each 20$\times$20 m plot. The distribution patterns by Morisita's Index showed that S. nigra was distributed randomly in all of the stands. The association analysis showed that the following tree species were positively associated with S. nigra. In other words, the following trees were appeared to require the same ecological niche together with S. nigra: Lindera erythrocarpa, Cornus waltri, Acer mono, and Styrax japonica.