Ulleung Island Research Articles

상온 환경에서 PEDB를 이용한 울릉도 시추코어의 열전도도 예비 측정

상온 환경에서 PEDB를 이용한 울릉도 시추코어의 열전도도 예비 측정

울릉도 산출 암석의 열물성 자료를 이용한 울릉도 지열 성인에 대한 열전도 수치모델링 연구

울릉도 산출 암석의 열물성 자료를 이용한 울릉도 지열 성인에 대한 열전도 수치모델링 연구

삼척과 울릉도의 신라고분 문화

삼척과 울릉도의 신라고분 문화

울릉 마가목의 클로로겐산 이성체의 최종당화산물의 생성 저해 및 라디칼 소거 활성

Advanced glycation end product (AGE) formation and reactive oxygen species are potential therapeutic targets for the prevention of diabetic nephropathy and other pathogenic complications. Activity-guided isolation of an ethylacetate-soluble portion of 80% methanolic extract from fruits of Sorbus commixta of the Ulleung Island origin using AGE formation inhibition assay led to the isolation and identification of three caffeoylquinic acid derivatives of a previously known structure, 3-O-caffeoylquinic acid (neochlorogenic acid; 1), 4-O-caffeoylquinic acid (cryptochlorogenic acid; 2), and 5-O-caffeoylquinic acid (chlorogenic acid; 3). The structures of these compounds were confirmed by interpretation of nuclear magnetic resonance and mass spectrometry data. Among the isolates, the major metabolite, neochlorogenic acid (1) showed the most potent inhibitory effect against AGE formation with an IC50 value of 167.5±3.5 μM. Furthermore, all isolated chlorogenic acid isomers were evaluated for their radical scavenging activity against peroxynitrite, and structurally related isomers 1, 2, and 3 exhibited potent inhibitory effects in this radical scavenging assay. This result suggests that the monocaffeoyl quinic acid derivatives isolated from S. commixta might be beneficial for the regulation of diabetic complications and related diseases.

Solar Farm Suitability Using Geographic Information System Fuzzy Sets and Analytic Hierarchy Processes: Case Study of Ulleung Island, Korea

Solar farm suitability in remote areas will involve a multi-criteria evaluation (MCE) process, particularly well suited for the geographic information system (GIS) environment. Photovoltaic (PV) solar farm criteria were evaluated for an island-based case region having complex topographic and regulatory criteria, along with high demand for low-carbon local electricity production: Ulleung Island, Korea. Constraint variables that identified areas forbidden to PV farm development were consolidated into a single binary constraint layer (e.g., environmental regulation, ecological protection, future land use). Six factor variables were selected as influential on-site suitability within the geospatial database to seek out increased annual average power performance and reduced potential investment costs, forming new criteria layers for site suitability: solar irradiation, sunshine hours, average temperature in summer, proximity to transmission line, proximity to roads, and slope. Each factor variable was normalized via a fuzzy membership function (FMF) and parameter setting based on the local characteristics and criteria for a fixed axis PV system. Representative weighting of the relative importance for each factor variable was assigned via pairwise comparison completed by experts. A suitability index (SI) with six factor variables was derived using a weighted fuzzy summation method. Sensitivity analysis was conducted to assess four different SI based on the development scenarios (i.e., the combination of factors being considered). From the resulting map, three highly suitable regions were suggested and validated by comparison with satellite images to confirm the candidate sites for solar farm development. The GIS-MCE method proposed can also be applicable widely to other PV solar farm site selection projects with appropriate adaption for local variables.

Eckol fromEisenia bicyclisInhibits Inflammation Through the Akt/NF-κB Signaling inPropionibacterium acnes-Induced Human Keratinocyte Hacat Cells

To investigate whether eckol, a phlorotannin compound from edible brown seaweed Eisenia bicyclis, could be responsible for the suppression of inflammatory processes, we examined the anti-inflammatory effects of eckol on Propionibacterium acnes-induced human skin keratinocytes (HaCaT) cells. P. acnes–treated HaCaT cells increased the expression of pro-inflammatory cytokines and chomokines. We also examined in vitro regulatory function of eckol on production of nitric oxide (NO), matrix metalloproteinase (MMP)−2 and MMP-9 as well as expression of inducible NO synthase, cyclooxygenase-2, and tumor necrosis factor-α. Eckol inhibited the expression or formation production of these proinflammatory mediators and cytokines in HaCaT cells. Additionally, treatment of HaCaT cells with P. acnes significantly increased protein kinase B (Akt) and nuclear factor kappa B (NF-κB) activation. Eckol inhibited P. acnes-mediated phosphorylation of Akt and activation of NF-κB in a dose-dependent manner. These results suggest that eckol could be a potential therapeutic agent to effectively treat the inflammatory skin disease induced by P. acnes. Practical Applications Eisenia bicyclis is a common perennial phaeophyceae (brown alga) and generally inhabits the region of Ulleung Island in the East sea of Korea. This edible seaweed is widely consumed in various ways such as appetizers, casseroles, muffins, pilafs, and soups. E. bicyclis also has various physiological properties such as antioxidant and anti-inflammatory activities because of their substantial quantities of phenolic compounds, constituted mainly by marine-derived polyphenols (phlorotannins). Eckol, one of phlorotannins from E. bicyclis, shows therapeutic effectiveness against viable P. acnes-induced inflammation in HaCaT cells. Thus, we suggest that eckol from E. bicyclis is a potential treatment for anti-inflammatory therapy for acne vulgaris.

울릉도 화산암류의 분화이력과 분출량에 따른 위험도 분석

울릉도 화산암류의 분화이력과 분출량에 따른 위험도 분석

Optimization of hybrid renewable energy power system for remote installations: Case studies for mountain and island

Various efforts are in progress to curb global warming and climate change. One of the solutions is to cut emission of CO2 from power plants. Decentralized power from renewable energy sources are ideal solution. This paper provides detail optimization procedure based on linear programming; for minimizing operation cost by utilizing maximum potential of REPS, and taking into consideration monthly fluctuation on generation and electricity demand. Hybrid system consisting of Hydropower, Photovoltaic and, Wind systems were taken into consideration for the optimization. Optimizations were performed for two cases, first being a remote mountainous Thingan village in Nepal and second a fairly large Ulleungdo island in South Korea. The two cases differ in demand scale, energy use, renewable energy potential, and geographic location. The optimization result show that for the HRES in Thingan, the Hydro power, Wind Power and PV power system should be 26.85 kW, 2.11 kW and 3.48 kW respectively. Similarly for Ulleungdo, optimized result for Hydro power, Wind Power and PV power was found to be 825 kW, 1291 kW and 1107 kW respectively. The optimization results indicate that the optimized hybrid system can help to completely switch from current fossil fuel dependence power system to renewable energy based power system in wide geography.

Viola woosanensis, a recurrent spontaneous hybrid between V. ulleungdoensis and V. chaerophylloides (Violaceae) endemic to Ulleung Island, Korea.

Ulleung Island is an oceanic volcanic island in Korea, which has never been connected to the adjacent continent. Previous studies highlighted Ulleung Island as an excellent system to study the pattern and process of early stages of flowering plant evolutions on oceanic island. The predominant mode of speciation in flowering plants on Ulleung Island appears to be anagenesis. However, the potentially important role of hybrid speciation among incompletely reproductively isolated lineages cannot be ruled out. Viola woosanensis (Violaceae) is of purportedly hybrid origin between V. ulleungdoensis (i.e., formerly recognized as V. selkirkii in Ulleung Island) and V. chaerophylloides, based on morphology. To examine the origin of V. woosanensis, we sampled a total of 80 accessions, including V. woosanensis and its putative parental species and sequenced nrDNA ITS, and four highly variable chloroplast noncoding regions (trnL-trnF, rpl16 intron, atpF-atpH, and psbA-trnH). Representative species of Viola from Korea were also included in the phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). Additive polymorphic sites in the nrDNA ITS regions were confirmed by cloning amplicons from representative species. The molecular data strongly supported the hybrid origin of V. woosanensis, and the maternal and paternal parent were determined to be V. ulleungdoensis and V. chaerophylloides, respectively. The presence of two parental ribotypes in V. woosanensis (with the exception in one population) was confirmed by cloning, suggesting V. woosanensis is primarily the F1 generation. No trace of backcrossing and introgression with its parents was detected due to low fertility of hybrid species. We found a multiple and unidirectional hybrid origin of V. woosanensis. Additional studies are required to determine which factors contribute to asymmetric gene flow of Viola species in Ulleung Island.

Temperature Variation in the Ulleung Warm Eddy during 2013~2015

Based on the Expendable Bathythermograph (XBT) observation and serial oceanographic observation of National Institute of Fisheries Science (NIFS) during July 2013 to July 2015, we examined the temperature variation in the Ulleung Warm Eddy (UWE) in the East Sea. The UWE was always shown during the observation periods even though it was not the whole shape. The coefficient of variation (CV) was largest in the depth of 250 m at the side of the east coast of Korean Peninsula with 3~4℃ in temperature. CV of the horizontal distribution at 250 m depth was also largest in the region biased along the east coast of Korea. The warm eddy moved not only to the east-west direction but also to the north-south direction in the viewpoint of horizontal distributions of temperature. This region between the Korean Peninsula and Ulleung island also is the passage of the East Korean Warm Current. This means that interaction between the East Korean Warm Current and periphery of warm eddy makes large in the variation of movement along the east coast of Korean Peninsula. The largest variation of temperature at 250 m depth seemed to be significantly correlated with the East Sea Intermediate Water (ESIW) underlying Ulleung Warm Eddy. It is suggested that the interaction between the ESIW and UWE is active in the mid-depth along the periphery of UWE.

703 Anti-aging potential of gypenosides fraction obtained from naturally grown Gynostemma pentaphyllum in Ulleungdo Island and its 7 new gypenosides

703 Anti-aging potential of gypenosides fraction obtained from naturally grown Gynostemma pentaphyllum in Ulleungdo Island and its 7 new gypenosides

울릉도 남해역에 서식하는 키조개의 연중 번식주기에 관한 연구

Gametogenesis of the comb pen shell, Atrina pectinata (Linnaeus, 1767) (Bivalvia: Pinnidae) on the southern coast of Ulleungdo Island, Korea was assessed monthly (November 2013 to October 2014) using histology. Gametogenesis commenced in January when the surface water temperature was 12.6℃ and pen shells evidenced an early development phase with small oogonia from January to April, although few females exhibited ripe eggs in their follicular epithelium. In April, the oocyte diameter increased rapidly, and fully mature eggs appeared in May. First spawning males and females were observed in June as the surface water temperature reached 19.3℃ and July (23.2℃) respectively. The spawning activity continued until the end of September. Histology indicated that the spawning peak of the females in Ulleungdo Island was July to August. During October to January, most of the pen shells were in spent and resting stages. Our data suggested that A. pectinata is a summer spawner, and their annual gametogenesis is closely associated with the seasonal variation in the surface water temperature. The present study is the first provided fundamental information on the life history of A. pectinata in Ulleungdo Island, and this can be put to good use in the management of this pen shell in the study area.

울릉도 마가목의 다양한 부위의 항혈전 활성

Sorbus commixta, a flowering plant in the Rosaceae family, is native to Japan and Ulleung Island, Korea. This plant is also called maga-mok or mai-mok in Korea because the bud of the stem has a similar shape to the teeth of a horse. In this study, hot water extracts from different parts of S. commixta, such as leaf, stem, and immature and mature fruits, were prepared, and their antithrombosis and antioxidant activities were evaluated. The extraction yield and pH of stem extracts were 3.99% and 5.5, respectively. The stem extracts contained 89.2 ㎎/g of total polyphenols and 28.3 ㎎/g of total flavonoids. The hot water extracts prepared from the leaf, stem, immature, and mature fruit of S. commixta exhibited no hemolytic activity against human red blood cells, up to a concentration of 0.5 ㎎/ml. In an anticoagulation assay, the stem extracts showed strong extension in thrombin, prothrombin, and activated partial thromboplastin times, whereas the other extracts had no anticoagulation activity. In a platelet aggregation inhibitory activity assay, all the extracts tested had no inhibitory activity against human platelets. With regard to antioxidation activity, the stem extracts showed stronger radical scavenging activity and reducing power activity than the other extracts. The calculated RC 50 s, the concentration required for 50% radical scavenging activity, for DPPH anions, ABTS cations, and nitrite of the crude stem extracts were 119.7, 53.3, and 117.5 ㎍/ml, respectively, whereas they were 13.7, 5.2, and 14.9 ㎍/ml for DPPH anions, ABTS cations, and nitrite, respectively, for vitamin C. The results suggest that the stem extracts of S. commixta have strong potential for use as a novel resource for antithrombosis agents.

Ancient and modern colonization of North America by hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae), an invasive insect from East Asia.

Hemlock woolly adelgid, Adelges tsugae, is an invasive pest of hemlock trees (Tsuga) in eastern North America. We used 14 microsatellites and mitochondrial COI sequences to assess its worldwide genetic structure and reconstruct its colonization history. The resulting information about its life cycle, biogeography and host specialization could help predict invasion by insect herbivores. We identified eight endemic lineages of hemlock adelgids in central China, western China, Ulleung Island (South Korea), western North America, and two each in Taiwan and Japan, with the Japanese lineages specializing on different Tsuga species. Adelgid life cycles varied at local and continental scales with different sexual, obligately asexual and facultatively asexual lineages. Adelgids in western North America exhibited very high microsatellite heterozygosity, which suggests ancient asexuality. The earliest lineages diverged in Asia during Pleistocene glacial periods, as estimated using approximate Bayesian computation. Colonization of western North America was estimated to have occurred prior to the last glacial period by adelgids directly ancestral to those in southern Japan, perhaps carried by birds. The modern invasion from southern Japan to eastern North America caused an extreme genetic bottleneck with just two closely related clones detected throughout the introduced range. Both colonization events to North America involved host shifts to unrelated hemlock species. These results suggest that genetic diversity, host specialization and host phylogeny are not predictive of adelgid invasion. Monitoring non-native sentinel host trees and focusing on invasion pathways might be more effective methods of preventing invasion than making predictions using species traits or evolutionary history.

동해안 울릉도 해역의 해조군집

A subtidal marine benthic algal vegetation at Ulleungdo Island, the eastern coast of Korea was investigated to clarify the community structure and vertical distribution by quadrat method at seven stations in May and August 2014. The total number of marine algal species was 148 species composed of the green algae of 12 species, the brown algae of 40 species and the red algae of 96 species. Mean biomass in dry weight was 94.8 g dry weight m -2 in study sites, 98.1 g dry weight m -2 in upper tidal level, and 86.6 g dry weight m-2 in middle level. The R/P and (R+C)/P value reflecting flora characteristic were 1.9 and 2.3, respectively. Three groups produced by cluster analysis, one including sites Neunggeol, Daepung, Jukdo, second including sites Gongam, Ssangjeongcho and the other including sites Gwaneum, Hangnam, showed meaningful difference in similarity (about 40%), each other. The number of marine algal species and biomass in Ulleungdo Island area were markedly reduced comparing that in the previous studies. This result may suggest probably change of algal vegetation in future, considering the physical and chemical pollutions loaded in the coastal marine environment of this area.

Japanese Recognition on Ulleungdo and Dokdo in Regard of the Case of Tenpo-Takeshima-Ikken(天保竹島一件)

Japanese Recognition on Ulleungdo and Dokdo in Regard of the Case of Tenpo-Takeshima-Ikken(天保竹島一件)

A Pre-feasibility Study on the Promotion of Hybrid Power System in Ulleung Island

A Pre-feasibility Study on the Promotion of Hybrid Power System in Ulleung Island

The Recognition of Japanese and Sovereignty Issues on Ulleungdo and Dokdo, appeared in Takeshima Magazine

The Recognition of Japanese and Sovereignty Issues on Ulleungdo and Dokdo, appeared in Takeshima Magazine

Genetic Consequences of Anagenetic Speciation in Endemic Angiosperms of Ullung Island, Korea

Genetic Consequences of Anagenetic Speciation in Endemic Angiosperms of Ullung Island, Korea

인공풍화가속실험을 통한 울릉도에 분포하는 화산암의 풍화특성 고찰

Artificial accelerated weathering test evaluated rocks from near the circuit road of Ulleungdo island, approximately 120 km from east of the Korean Peninsula. The tests subjected rock specimens to conditions based on the climate of the island. The specimens (such as basaltic breccia, trachyte, volcanic breccia) were preliminarily classified using a TAS diagram (XRF data) and based on the constituent minerals (XRD data); they were further classified by weathering degree according to their absorption ratios. During the artificial accelerated weathering, the absorption ratio of most of the specimens increased, but the point-load strength did not decrease in most cases, except for the volcanic breccia. The greater initial absorption ratio of trachyte rock specimen in comparison with the other specimens led to a greater increase of its absorption ratio during the artificial accelerated weathering test. The volcanic breccia specimens showed the greatest increase of absorption ratio and the biggest reduction ratio of the point- load strength during the tests. These results could aid prediction of the weathering rate of rocks in Ulleungdo island subjected to weathering processes; trachyte which appears to accelerate with time, and volcanic breccia whose mechanical strength can largely decrease in a relative short period of time. Proper measures therefore appear necessary for the prevention of natural disaster such as rock fall and landslide around the circuit road.