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이 논문의 목적은 메이지 시대 초기 최초의 아이누 교육기관이었던 ‘개척사가학교부속홋카이도토인교육소’에서의 아이누민족 교육에 대하여 고찰하는 것이다. 근대 이전까지 일본 안의 외국인이었던 아이누민족은 메이지 유신 이후 일본에 편입되었다. 메이지 정부는 러시아와 국경 문제로 민감한 홋카이도 개척을 위해 1869년 7월 홋카이도에 개척사를 설치하였다. 개척차관이었던 구로다 기요타카(黑田淸隆)는 아이누민족을 교화시키기 위하여, 홋카이도 아이누인 100명을 도쿄에 데려가 교육할 계획을 세우고 실행하였다. 그러나 개척사는 철저한 계획과 준비도 없이 아이누민족을 도쿄로 데려가서 임기응변식 교육을 하였다. 개척사의 처음 계획은 아이누민족에게 농업기술을 가르치는 것이었는데, 이후 어린 생도는 ‘개척사가학교부속홋카이도토인교육소’에서 읽기와 쓰기 산술 교육을 하였다. 개척사는 도쿄에서의 교육을 통하여 아이누민족의 풍속과 습관, 사상 등의 일본화를 시도하였다. 이런 강제적인 시도를 아이누 생도들 쪽에서 반발하여 1년 정도 지나자 도망자와 사망자가 생겼다. 홋카이도토인교육소에서의 아이누민족에 대한 교육은 실패했다고 평가하였다. 대부분의 생도는 가나를 쓸 정도의 수준밖에 안 되었다. 이때의 실패로 인해 아이누민족에 대한 교육을 다시 시작하는 데는 몇 년의 시간이 걸리게 되고, 지방에서 소학교를 설립하면서 다시 교육이 시도된다.

In recent years, stringent environmental regulations for air pollution have led to increased demand for liquefied natural gas (LNG). Therefore, the demand for the design and construction of LNG-fueled vessels has also increased. One of the most important points for the design of LNG-fueled vessels is the structural integrity of the LNG fuel tank, particularly at cryogenic temperatures. Low temperature materials are used in the construction of LNG fuel tanks to ensure structural safety. Among the various low temperature materials, nickel steel is commonly employed for the design of LNG storage tanks. In addition, Shielded Metal Arc Welding (SMAW) and Submerged Arc Welding (SAW) are commonly applied to the construction of LNG storage tanks. On the other hand, the application of Flux Cored Arc Welding (FCAW) for nickel steel as an alternative to SMAW and SAW appears to be necessary, considering the high productivity. Nevertheless, there have been few studies of the fracture behavior of nickel steel with FACW compared to SMAW and SAW processes. This study examined the fracture characteristics of 9% nickel steel and weldments considering application for the LNG storage tanks. The fracture characteristics of FCAW was compared with SMAW at 25°C and − 163°C temperatures. As the result, the mechanical properties with FCAW were higher than those with SMAW at 25°C and − 163°C. In addition, SMAW is slightly better than FCAW in terms of the impact absorbed energy. Moreover, the crack tip opening displacement (CTOD) values of the weld metal and heat affected zone (HAZ) with FCAW were higher than those with SMAW.

Coastal vegetated habitats such as mangroves, salt marshes, and seagrasses, referred to as blue carbon ecosystems, play an important role in climate change mitigation by an effective CO

Background The transmission mode of severe acute respiratory syndrome coronavirus 2 is primarily known as droplet transmission. However, a recent argument has emerged about the possibility of airborne transmission. On June 17, there was a coronavirus disease 2019 (COVID-19) outbreak in Korea associated with long distance droplet transmission. Methods The epidemiological investigation was implemented based on personal interviews and data collection on closed-circuit television images, and cell phone location data. The epidemic investigation support system developed by the Korea Disease Control and Prevention Agency was used for contact tracing. At the restaurant considered the site of exposure, air flow direction and velocity, distances between cases, and movement of visitors were investigated. Results A total of 3 cases were identified in this outbreak, and maximum air flow velocity of 1.2 m/s was measured between the infector and infectee in a restaurant equipped with ceiling-type air conditioners. The index case was infected at a 6.5 m away from the infector and 5 minutes exposure without any direct or indirect contact. Conclusion Droplet transmission can occur at a distance greater than 2 m if there is direct air flow from an infected person. Therefore, updated guidelines involving prevention, contact tracing, and quarantine for COVID-19 are required for control of this highly contagious disease., Graphical Abstract

Resumo Este artigo tem como objeto o livro de poesias Chiclete de Kim Ki-taek, publicado originalmente em 2009 na Coreia e em 2018 no Brasil pela editora 7Letras. O primeiro poeta contemporâneo coreano traduzido para a língua portuguesa é representante de uma poesia coreana urbana, revelando qualidades inumanas da vida megalopolizada e transitando por temas comuns à civilização internacional. Apesar de abordar temas comuns a grandes cidades do mundo contemporâneo, as dificuldades de tradução na passagem entre línguas tão distantes são sempre desafiadoras. Neste artigo, foram selecionadas expressões ligadas a cheiros, pois estas constituem um elemento chave na poética de Kim Ki-taek, e também exemplificam várias questões complexas que envolvem a tradução de aspectos culturais e semânticos entre as duas línguas. Ao analisar cada vocábulo e a sua respectiva tradução, e comparando com a tradução para o espanhol, procurou-se mostrar a necessidade de recorrer a variados procedimentos em busca de um equivalente poético adequado. Abstract The object of this article is Gum, book of poems by Kim Kitaek, originally released in Korea in 2009 and published in Brazil by 7Letras publishing house in 2018. The first Korean contemporary poet introduced to Brazilian readers is a representative of an up-to-date Korean urban poetry, revealing a non-humane quality of a megalopolitan life and transiting through common themes to the international civilization. Despite its approach to common themes to big cities of the contemporary world, the difficulties in translating such immensely different languages are always challenging. In this article, it was selected expressions referring to smells, for these constitute a very important element in Kim Ki-taek’s poetry and also bring about complex issues involving translation of cultural and semantic aspects between the two languages. By analyzing each selected word and its translation, and comparing it with the translation into Spanish as well, it turned out to be clear the search for diverse translation procedures to reach for an adequate poetic equivalent.

Park, J.-I.; Kim, j.-H.; Kim, J.H., and Shim, J.H., 2018. A New and Effective Transplanting Technique Using Wire Netting for Restoration of the Surfgrass, Phyllospadix japonicus, in Exposed Rocky Shores. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 326–330. Coconut Creek (Florida), ISSN 0749-0208. The surfgrass Phyllospadix japonicus is an abundant seagrass along the exposed rocky shores of the Korean peninsula. However, many surfgrass meadows on this area have been severely damaged by anthropogenic factors, leading to a growing interest on the restoration of surfgrass habitats. Few attempts have been made to develop transplanting techniques for surfgrass, owing to the low transplant survival in high-energy rocky shores. The present study evaluates the performance of a new transplantation method for P. japonicus based on affixing surfgrass transpla...

Kim, J.B.; Kim, H.C.; Hong, S., and Park, J.-I., 2018. Mixed Aquaculture of Anadara broughtonii and A. kagoshimensis (Bivalvia: Arcidae) in Jinju Bay on the South Coast of the Korean Peninsula. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 341–345. Coconut Creek (Florida), ISSN 0749-0208. The biological characteristics and potential food resources of Anadara broughtonii and Anadara kagoshimensis were investigated from May 2013 to December 2014 to evaluate the effects of culturing the two species together (mixed aquaculture). There was no difference in sea water temperature between the surface and bottom layers, and salinity decreased after high rainfall. The three sites used as test shellfish farms had high mud contents and similar concentrations of chemical parameters in the sediment. To identify the potential food sources of the two species, carbo...

For the first time, this paper proposes natural seagrass based prominent ocean flowering and bio-friendly material for triboelectric nanogenerator (TENG) through a simple spray coating technique. Herein, two different seagrass species (Zostera marina and Phyllospadix japonicus) are effectively applied as a tribopositive material. Furthermore, spray coatable Phyllospadix japonicus seagrass film/PET TENG yields a higher power density of 70.42 μW/cm2 compared to Zostera marina seagrass film/PET TENG of 50.42 μW/cm2 because of the higher oxygen functional groups, which enables the device to offer increased electron-donating capability. Moreover, the output performance of the proposed spray coatable TENG device improved by about 31% compared to powder-based seagrass film. Furthermore, the Phyllospadix japonicus based TENG presents the extraordinary working stability up to 72,000 cycles (2 h), which confirms the excellent robustness of the fabricated device. It is further demonstrated that the proposed Phyllospadix japonicus based TENG can easily charge various commercial capacitors and capable of driving about 150 light-emitting diodes (LEDs), and other microelectronic devices. We anticipate that by applying seagrass as a tribopositive layer, the proposed spray coatable TENG device will serve its promising role for energy generation with extremely low fabrication cost. Furthermore, in addition to the economic use of seagrass as a TENG, this work can favorably contribute to sustainable seagrass management.

Among the seagrasses that occur along the coast of Korea, Zostera asiatica inhabits the deepest depth; however, to date, there is limited information on its ecology. This study presents the first quantitative data on the seasonal growth dynamics of Z. asiatica in Korea. We measured seasonal growth and morphological characteristics, as well as environmental factors, including underwater irradiance, water temperature, salinity and nutrient concentrations of the water column and sediment pore water, bimonthly from July 2012 to May 2015. Underwater irradiance showed clear seasonal trends, increasing in the spring and summer and decreasing in the fall and winter, ranging from 2.4 ± 0.2 mol photons m-2 d-1 in November 2012 to 12.8 ± 1.3 mol photons m-2 d-1 in July 2014. Water temperature also followed a strong seasonal trend similar to underwater irradiance, ranging from 9.8 ± 0.1°C in January 2013 to 20.5 ± 0.2°C in September 2013. Nutrient availability fluctuated substantially, but there was no evidence of distinct seasonal variations. Shoot density, biomass, leaf productivity, and morphological characteristics of Z. asiatica exhibited significant seasonal variations: maximum values of these variables occurred in summer, and the minima were recorded in winter. Total shoot density was highest (218.8 ± 18.8 shoots m-2) in July 2012 and lowest (106.3 ± 6.3 shoots m-2) in January 2013. Total biomass ranged from 182.6 ± 16.9 g dry weight (DW) m-2 in January 2015 to 310.9 ± 6.4 g DW m-2 in July 2014.Areal leaf production was highest (4.9 ± 0.0 g DW m-2 d-1) in July 2012 and lowest (1.4 ± 0.2 g DW m-2 d-1) in January 2013. The optimum water temperature for the growth of Z. asiatica was between 16-19°C. Growth of Z. asiatica was more strongly correlated with underwater irradiance than water temperature, suggesting that light is the most important factor determining seasonality of Z. asiatica at the study site.

The growth and reproduction of the marine seagrass foundation species Zostera marina (eelgrass) are threatened by rising sea surface temperatures (SSTs). After both natural and anthropogenic disturbances, the recovery of Z. marina largely depends on seed germination and seedling establishment. Therefore, understanding the effects of increasing water temperature on the phenology and intensity of flowering is critical for predicting the persistence of Z. marina and its associated ecosystems. The effects of increasing SST on Z. marina flowering were investigated using long-term records (2002–2018) of Z. marina flowering and daily SSTs along the southern coast of Korea. Significant SST increases occurred during the study period. The annual maximum SST increased at a faster rate than the annual mean SST, whereas no warming trend was observed for the minimum winter temperature. Gradual declines in the reproductive intensity of Z. marina were observed during 2011–2018, when annual mean SST increased rapidly and summer marine heatwave (MHW) events became more intense and frequent. Reproductive parameters such as flowering shoot density, flowering frequency, and reproductive allocation showed significant negative relationships with mean SSTs. Thus, increasing heat stress due to sea warming would have led to decreased reproductive output of Z. marina over the study period. The results of this study suggest that warmer water temperature in the future may decrease the reproductive performance of Z. marina and limit this species’ capacity for recovery via seedling recruitment. Measuring long-term sexual reproduction in Z. marina may be useful as a bioindicator of sea warming and will improve our understanding of seagrass responses to climate change.

본 연구에서는 외모를 강조하는 대중매체에 과다하게 노출된 여자청소년들이 신체이미지와 자기존중감에서 어떤 변화를 보이는지 확인하고자 하였다. 경기지역에 소재한 중학교 1개교와 고등학교 1개교에 재학 중인 386명의 여자청소년을 임의 표집하여 집단설문조사를 시행하였다. 연구결과 외모를 강조하는 대중매체에 대한 노출 정도가 높더라도 여자청소년들의 외모에 대한 사회문화적인 태도(내면화 정도와 인식하는 정도)는 더 예민하지는 않았지만, 외모에 대해서는 더 불만족했다. 또한 대중매체에 대한 노출 정도에 관계없이 자기존중감이 높을수록 외모에 대한 사회문화적인 태도를 내면화하고 인식하는 정도가 더 작았으며, 외모추구형메시지를 받아들이는 정도도 유의하게 더 적었다. 그러나 자기존중감이 높을수록 오히려 외모에 대해 더 예민했으며 자신의 신체상에 관해서도 더 불만족한 것으로 나타났다. 접촉하는 대중매체의 종류에 따라 외모에 대한 태도 및 신체이미지에 미치는 영향은 다르게 나타났다. 외모지향성에 영향을 미치는 대중매체가 뮤직비디오, 스마트폰인 것은 매체에 대한 접근성이나 편의성이 크기 때문으로 해석되었다. 본 연구에서는 청소년들의 심리적 적응과 정체감 등에 영향을 미치는 자기존중감의 탄력적 효과에 대해 시사적인 정보가 된다는 점과 외모관리행동 등을 비롯하여 청소년들의 생활방식을 확인하는 기초 자료가 될 수 있음을 논의하였고 청소년들의 자아개념에 영향을 미치는 원인이자 결과인 학업성취도나 성별차이, 발달상의 연령효과 등을 고려하지 못한 점을 한계로 제시하였다.

The seagrass Zostera japonica occurs mainly in the intertidal zone and is thus exposed to widely varying environmental conditions affecting its growth and distribution compared to subtidal seagrasses. The growth dynamics of Z. japonica at its upper and lower distributional limits in the intertidal zone were investigated in Koje Bay on the southern coast of Korea to examine the environmental stresses and limiting factors on the growth of intertidal seagrasses. The shoot density and morphology, biomass, and leaf productivity of Z. japonica were measured in relation to coincident measurements of environmental factors at its upper and lower distributional limits and in an intermediate zone of the intertidal area. The mean exposure time to the atmosphere during low tide in the upper intertidal zone was approximately 1.5- and 1.9-fold longer than that in the intermediate and lower intertidal zones, respectively. Shoot density and biomass were significantly higher in the intermediate zone than at the upper and lower distributional limits. Longer emersion leading to a various of environmental stresses appeared to reduce Z. japonica growth in the upper intertidal zone, whereas interspecific competitive interactions related to irradiance seemed to affect Z. japonica growth in the lower intertidal zone. Shoot size, density, biomass, and leaf productivity were lower in the upper than in the lower zone, implying that emersion-associated stresses in the upper zone had a greater detrimental effect on Z. japonica growth than did stresses occurring in the lower zone. The productivity of Z. japonica showed strong positive correlations with air and water temperature, suggesting enhancement of Z. japonica production at higher temperatures. Thus, the predicted increases in air and water temperature associated with global climate change might have positive effects on the growth and extension in distributional range of this species.

This study was to examine the effectiveness of Positive Psychology Group Program in Korea by using method of meta-analysis. For the purpose of the study, master`s theses, doctoral dissertations, and journal articles published in Korea up to June, 2015 were systematically reviewed. As a result, a total of 26 studies were eligible for the inclusion criteria. The mean effect sizes and test for homogeneity of effect size(Q-statistic) were analyzed by using Comprehensive Meta-Analysis software 2.0. The main findings of the study were as follows. First, the average effect sizes for Positive Psychology Group Program were ES

Purpose The purpose of this retrospective study was to determine the 3-year mechanical complication rates of the most distally positioned implant-supported single crowns (ISSCs) in the posterior region, and how these complication rates are affected by several clinical factors (i.e., gender, mean age, horizontal distance [HD], position in the jaw, placement location, duration of functional loading, clinical crown-to-implant length ratio [C/I ratio], and crown height space of the implant). Materials and Methods The mechanical complications (i.e., abutment screw loosening [ASL], abutment screw fracture [ASF], and ceramic fracture [CF]) associated with the implants were identified by examining the patients’ treatment records, clinical photographs, and intraoral periapical radiographs. Statistical analyses were performed using chi-square and Student's t-test to identify the relationship between various clinical factors and the mechanical complication rates. Receiver operating characteristics analysis was conducted to determine the optimal cut-off value for the HD between the most distally positioned ISSCs and the mesially adjacent natural tooth beyond which complications occur. Results The study inclusion criteria were met by 183 patients who had undergone implant surgery in the period 2004 to 2011, involving a total of 221 implant treatments. Mechanical complications were present in 40 (18.1%) of the 221 investigated ISSCs. ASL was the most common complication (n = 28, 12.7%), followed in order by CF (n = 9, 4.1%) and ASF (n = 3, 1.4%). Repeated ASL and CF occurred in four (1.8%) and two (0.9%) implants, respectively. The mechanical complication rates differed significantly between implants with different HDs (p = 0.009) and clinical C/I ratios (p = 0.019); however, there was no significant association between the other clinical factors and the mechanical complication rates. Conclusion Within the limitations of this study, it appears that the incidence of mechanical complications is higher for the most distally positioned ISSCs in the posterior region than for those positioned at other sites. Furthermore, since the rate of mechanical complications increases with increasing HD, an HD of 3.7 mm or less is recommended.

Zostera caulescens is an endemic seagrass species in Northeastern Asia. Estimated distributional area of this species is approximately 1–5 km2 on the coasts of Korea. Because Z. caulescens has a very limited distribution, the growth dynamics of Z. caulescens is little known in the coastal waters of Korea. In the present study, we investigated the growth dynamics of Z. caulescens in relation to coincident measurements of environmental factors, such as underwater irradiance, water temperature, and nutrient availability. The study was conducted on a monotypic meadow of Z. caulescens in Uljin on the eastern coast of Korea from September 2011 to September 2012. Shoot density and biomass of Z. caulescens showed distinct seasonal variations, and exhibited strong correlations with water temperature suggesting that the seasonal growth of this species was regulated by water temperature. Shoot density and biomass rapidly decreased during the high water temperature period in summer, and thus Z. caulescens is considered a cold water adapted species like other temperate seagrass species on coasts of Korea. Biomass of photosynthetic leaf tissues on reproductive shoots was approximately 4 times higher than that on vegetative shoots. The height of reproductive shoots ranged from 1.2 m in February 2012 to 3.2 m in August 2012, whereas the height of vegetative shoots was usually less than 1.0 m. Leaf tissues on reproductive shoots probably received much more light for photosynthesis than those on vegetative shoots. Thus, reproductive shoots may play an important role in total production of Z. caulescens.

Phyllospadix japonicus is an abundant surfgrass that thrives mainly along the exposed rocky shores of Northeastern Asia. On the eastern coast of Korea, surfgrass populations have been adversely affected by increasing human pressures. We developed a seeding method using an artificial reef for the restoration of P. japonicus. In January 2005, we planted P. japonicus seeds on the lower part of coarse hemp-plant brush that was embedded densely on the concave surface on the top of artificial reefs. The reefs were then installed on an exposed rocky shore. To evaluate the feasibility of this seed-based surfgrass restoration technique, we monitored the seedling/shoot density and morphological characteristics of the shoots over a 2-year period. Seedlings began to emerge within the first month after seeding, reaching densities of up to 275.0 shoots m-2 by April 2005. After an initial decline, shoot density increased through the production of lateral shoots, and densities of up to 997.1 shoots m-2 were observed by the end of the experiment. Shoot height, the number of leaves, and leaf width rapidly increased during the first year after seeding, whereas the number of rhizome internodes and rhizome length rapidly increased during the second year. The P. japonicus shoots exhibited approximately 63.4 mm of rhizome elongation during the study period. Because seeded P. japonicus on the artificial reefs were successfully established at the study site, this seeding method using an artificial reef may offer an effective approach to restoring surfgrass habitat.

Significant losses in seagrass coverage have been reported worldwide, and thus efforts are under way to restore disturbed seagrass habitats. Unfortunately, rates of seagrass restoration success through transplantation remain quite low, and inappropriate transplant times may be one cause of the low success rates. To determine suitable seasons for transplanting eelgrass, transplantation experiments were conducted seasonally. After each transplantation trial, shoot density, chlorophyll content, shoot morphology, and productivity of transplants and reference plants were monitored at 2–4-week intervals for approximately 3 months. All eelgrass transplants had disappeared by the end of the summer transplantation trial, whereas transplant density increased most rapidly in the fall transplantation. High water temperature in summer appeared to be a primary seasonal stress in eelgrass meadows, causing high transplant mortality. Results for shoot morphology, physiology, and growth of transplants indicated that those planted in summer suffered the most severe transplanting stress, whereas those planted in fall experienced the least stress. Accordingly, summer transplantation for eelgrass restoration should be avoided in areas where summer water temperatures are greater than 25 °C. Because transplants planted in fall exhibited the highest expansion of shoots and suffered the least transplant stress, the optimal season for eelgrass transplantation is likely to be fall, just after the high water temperature period.

거머리말 종자의 적절한 저장 방법과 저장 가능한 기간을 알아보기 위하여 우리나라 남해안에서 채취한 거머리말 종자를 이용하여 다양한 저장 방법과 저장 기간 후 발아율을 조사하였다. 거머리말 종자의 저장 방법은 공기가 공 급되는 실온의 해수, 4 oC의 해수, 30 oC의 해수, 해수가 공급되는 수조, 밀폐된 해수, 냉동, 건조의 방법으로 저장하 였다. 4 oC의 해수에 저장한 거머리말 종자의 발아율이 가장 높았으며(52.0%), 해수가 유입되는 수조와 실온에서 저 장한 종자의 발아율은 각각 17.7%와 27.4%가 나타난 반면, 건조, 냉동한 종자와 30 oC의 해수에 보관한 종자는 전 혀 발아하지 않았다. 거머리말 종자의 각 저장 기간은 10, 20, 30, 60, 180일과 240일 동안 저장하였다. 10~60일 동 안 저장한 거머리말 종자는 46.4~52.4%의 발아율을 유지하였으나, 저장 기간이 길어질수록 급격히 발아율이 감소 하여, 240일 저장한 거머리말은 전혀 발아되지 않았다.

To determine the optimal storage method and longest possible storage period of Phyllospadix japonicus seeds, we examined post-storage germination rates using different storage methods and periods for P. japonicus seeds harvested in Korean coastal waters. P. japonicus seeds are classified as recalcitrant seeds with an average moisture content of 45.4%. Germination rates of P. japonicus seeds stored in seawater at 4 °C, seawater at room temperature with air supply, and an aquarium with continuous seawater circulation ranged from 35.0% to 43.5%, whereas seeds stored in seawater at 30°C, a refrigerator at −20°C, and a desiccator at room temperature did not germinate. Seeds stored at 4°C maintained germination rates of 72.5∼73.0% until 30 days of storage, but showed rapidly decreasing germination rates after 60 days and no germination after 180 days. Since few studies have investigated seed storage of P. japonicus, these results will serve as useful data for seed-based P. japonicus habitat restoration.

The aim of this study was to determine the efficacy of crosslinked collagenated porcine bone (CPB) for the repair of surgically prepared one-wall intrabony defects in dogs. Buccolingually opened, one-wall, box-type periodontal defects (4 × 5 mm) were prepared bilaterally at the mesial side of the mandibular fourth premolars in beagle dogs (N = 5). Block-type CPB (4 × 5 × 5 mm) was placed on either the left or right side for the CPB site; the opposite site served as a sham-surgery control. Micro-computed tomographic and histological analyses were performed on block specimens obtained from the dogs after a 3-month healing period. There was less mean bone regeneration and cementum regeneration at the experimental sites than at the sham-surgery control sites. Most of the porcine bone particles were located under the floor of the defect and were sequestered from pristine bone. These findings show that CPB can be localized within the defect during the wound-healing period by a process of crosslinking; however, the application of CPB alone without a barrier membrane may not be effective in promoting periodontal regeneration in noncontained-type defects. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1454–1461, 2014.

To select the optimal site for the restoration of seagrass habitats in the Taehwa River estuary, we transplanted the eelgrass Zostera marina to three potential candidate sites in March 2007 and monitored the transplanted seagrass and associated environmental factors for six months. In all three sites, the transplanted seagrasses exhibited no initial morphological loss due to transplanting stress. The transplanted seagrass communities at sites 2 and 3 showed more than a 180% increase in density over the entire survey period. In contrast, despite a density increase in the first month after transplantation, most of the transplanted seagrasses at site 1 died. This may be due to the large decrease in underwater irradiance reaching the seagrass leaves at site 1 for two months during June and July, which fell below the level of compensation irradiance. The growth rate and size of the seagrass shoots were also larger at sites 2 and 3 compared with site 1. This is probably due to higher nutrient concentrations in the sediment pore water at sites 2 and 3 compared with site 1, although water depth, salinity, and the nutrient concentrations in the water columns from the three sites were similar. Therefore, for the restoration of seagrass habitats in the Taehwa River estuary, sites 2 and 3 were preferable to site 1 as transplantation sites.

To examine the growth dynamics of eelgrass, Zostera marina, in the intertidal zone of Seomjin Estuary, Korea, we surveyed environmental factors such as water temperature, underwater irradiance, tidal exposure, and nutrient concentrations in the water column and sediment pore water in relation to the shoot density, biomass, morphological characteristics, and growth of Z. marina inhabiting the upper and lower intertidal zones. The survey was conducted monthly from January 2003 to December 2004. The water temperature of the two areas displayed seasonal fluctuations. Underwater irradiance was significantly higher in the upper intertidal zone than in the lower intertidal zone. Tidal exposure was also markedly longer in the upper intertidal zone than in the lower intertidal zone, whereas tidal exposure was highest in the spring and lowest in the summer in both areas. Water column NH4 + and sediment pore water NO3 −+NO2 − concentrations were significantly higher in the upper intertidal zone than the lower intertidal zone. The eelgrass shoot density, biomass, morphology, and leaf productivity were significantly higher in the lower intertidal zone than in the upper intertidal zone. Both areas displayed a clear seasonal variation depending on changes in water temperature. However, leaf turnover time was significantly shorter in the upper intertidal zone than in the lower intertidal zone, with a higher turnover rate in the upper intertidal zone. Compared to the seagrasses in the lower intertidal zone, those in the upper intertidal zone showed more effective adaptations to the stress of long tidal exposure through downsizing and increased turnover time. These results suggest that tidal exposure, coupled with desiccation stress, can be a limiting factor for seagrass growth in the intertidal zone, along with underwater irradiance, water temperature, and nutrient availability.

To study the difference in growth characteristics between intertidal and subtidal eelgrass Zostera marina populations, environmental factors and changes in tissue carbon (C) and nitrogen (N) contents in eelgrass from the lower intertidal and upper subtidal zones were surveyed monthly in the Seomjin Estuary from May 2003 to December 2004. Water temperatures, water column nutrient concentrations, sediment pore water, and ammonium and phosphate concentrations showed no significant differences between intertidal and subtidal zones. Sediment pore water nitrate+nitrite concentrations were slightly higher in the intertidal zone than in the subtidal zone. Average monthly exposure times in the intertidal and subtidal zones were 42.4±5.8 h month-1 and 15.3±3.5 h month-1, respectively. Eelgrass leaf N content decreased from March to August and increased from September to February in the subtidal zone, whereas these trends were not observed in the intertidal zone. Eelgrass rhizome C content increased from April to September and decreased from October to March in the subtidal zone, whereas those tendencies were not recorded in the intertidal zone. Eelgrass rhizome C:N ratios showed a strong reverse trend to leaf C:N ratios in the subtidal zone, but these tendencies were not observed in the intertidal zone. The effects of exposure appeared to cause no seasonal trend in eelgrass tissue C and N content or C:N ratios in the intertidal zone in the Seomjin Estuary.

The purpose of this retrospective study was to determine the 3-year mechanical complication rates of the most distally positioned implant-supported single crowns (ISSCs) in the posterior region, and how these complication rates are affected by several clinical factors (i.e., gender, mean age, horizontal distance [HD], position in the jaw, placement location, duration of functional loading, clinical crown-to-implant length ratio [C/I ratio], and crown height space of the implant).The mechanical complications (i.e., abutment screw loosening [ASL], abutment screw fracture [ASF], and ceramic fracture [CF]) associated with the implants were identified by examining the patients' treatment records, clinical photographs, and intraoral periapical radiographs. Statistical analyses were performed using chi-square and Student's t-test to identify the relationship between various clinical factors and the mechanical complication rates. Receiver operating characteristics analysis was conducted to determine the optimal cut-off value for the HD between the most distally positioned ISSCs and the mesially adjacent natural tooth beyond which complications occur.The study inclusion criteria were met by 183 patients who had undergone implant surgery in the period 2004 to 2011, involving a total of 221 implant treatments. Mechanical complications were present in 40 (18.1%) of the 221 investigated ISSCs. ASL was the most common complication (n = 28, 12.7%), followed in order by CF (n = 9, 4.1%) and ASF (n = 3, 1.4%). Repeated ASL and CF occurred in four (1.8%) and two (0.9%) implants, respectively. The mechanical complication rates differed significantly between implants with different HDs (p = 0.009) and clinical C/I ratios (p = 0.019); however, there was no significant association between the other clinical factors and the mechanical complication rates.Within the limitations of this study, it appears that the incidence of mechanical complications is higher for the most distally positioned ISSCs in the posterior region than for those positioned at other sites. Furthermore, since the rate of mechanical complications increases with increasing HD, an HD of 3.7 mm or less is recommended.

Objectives: This study was performed to investigate the service needs of the beneficiaries who had enrolled in home-based management programs for cancer patients. Methods: From March to May 2009, 676 cancer patients who were registered in home-based cancer patient management programs were selected as subjects for this study. The data were collected using a questionnaire along with a face-to-face interview performed by officers in charge of the home-based care programs of 47 regional health centers. Fifteen patients were excluded due to incomplete data, leaving 661 subjects who were ultimately enrolled in the study. Results: The mean age of subjects was 64.0 ± 12.5 years, and males comprised 45.1% (298/661) of the sample. The results of factor analysis for service needs showed that there were five main categories and Cronbach's alpha ranged from 0.593 to 0.890 for each factor. The service needs categories in order of importance were social support, information and education, psychological problems, physical symptoms and household chores. The service needs scores were significantly different when subjects were stratified by age, habitation, religion and disease classification. When we divided the subjects into complete remission, under treatment and terminally ill groups, the needs scores of the terminally ill patient group were significantly higher than those of the other groups (p

Among common estuarine submerged plants, seagrasses are the most extensively studied due to their ecological importance in estuarine ecosystems. Seagrass meadows are important biological habitats for a wide variety of marine animals and plants. They are a source of organic carbon for commercially important animals. Furthermore, seagrasses act as nutrient filters in estuarine and coastal marine ecosystems. As such, mapping the distribution of seagrass beds is important for management and conservation strategies. In order to survey the seagrass distribution within the Seomjin Estuary, We directly observed seagrass beds in Kwangyang and Hadong using SCUBA. The distribution area, species composition, morphology, density, biomass and productivity of seagrass meadows were examined. Seagrass meadows were distributed in the intertidal and subtidal zones of the Galsa tidal flats, and in the subtidal zone of the neighboring POSCO area. Patches of Zostera japonica was found at patches at the Galsa tidal flats intermediate point. The total estimated seagrass distribution area of the Seomjin Estuary was . Of the total, was Zostera marina (eelgrass) and was Zostera japonica (dwarf eelgrass). Zostera japonica was found in intertidal zones. Zostera marina was found from the intertidal to subtidal zones at a 2 m mean sea level (MSL) depth. The leaf productivity of Zostera marina was . The annual production of eelgrass was , which corresponds to . The total production of eelgrass was , which corresponds to .

Since significant seagrass declines have been reported worldwide, numerous seagrass restoration projects through transplantation have been attempted in recent decades. In this study, Zostera marina shoots were transplanted into Jindong Bay on the southern coast of Korea in November 2006 to assess establishment success of the transplants to a new transplant environment. Shoot density, individual shoot weight, productivity, and morphological characteristics of transplants and reference plants in the vicinity of the planting site were monitored monthly for 13 months. Although shoot size of transplants was smaller than that of reference plants at the start of transplantation, individual shoot weight, leaf width, shoot height, and rhizome diameter of transplants increased rapidly, reaching even higher values than those of reference plants 5 months after transplantation. These results suggest that eelgrass transplants established morphologically 5 months after transplantation. Shoot productivity of transplants was lower than that of reference population during the first 5–6 months following transplantation, but became higher than that of reference population 6 months after transplantation. The higher transplant productivity was likely due to the lower shoot density at the transplant site than that at the reference population. Rapid changes in shoot morphology and growth of transplants indicated that eelgrass transplants had great morphological plasticity and established successfully in the new environment within 5–6 months. In addition to survival rates of transplants, monitoring of shoot morphology and growth appeared to be an effective approach for accurate assessment of the establishment success of eelgrass transplant.

To test the feasibility of using chlorophyll a fluorescence to assess the establishment success of seagrass transplants, photosynthetic characteristics of eelgrass Zostera marina transplants were measured using a Diving-pulsed amplitude modulation fluorometer in Jindong Bay on the south ern coast of Korea. Maximum quantum yield (F v /F m ), photosynthetic efficiency ( α), saturating irradiance (E k ) and maximum electron transport rate (ETR max ) of transplants and reference plants in a nearby transplant site were measured using the fluorometer for 5 months. Additionally, shoot morphology, individual shoot weight and productivity of transplants and reference plants were also monitored. Shoot height, leaf weight and productivity of transplants were significantly reduced during the first two or three months after transplantation compared to those of reference plants, and then increased to the levels of reference plants. Characteris- reference plants. Characteris- plants. Characteris- s. Characteris-Characteris- haracteris- tics of chlorophyll a fluorescence, including F v /F m , α, E k and ETR max of transplants were also significantly reduced in the initial period, but recovered slightly sooner than shoot morphology or leaf productivity. These results indicated that after transplantation, Z. marina transplant photosynthesis recovered faster than shoot morphology, biomass or productivity. Thus, chlorophyll a fluorescence can be used as an indicator for early assessment of the status of eelgrass transplants without destructive sampling.

The surfgrass Phyllospadix japonicus is an abundant seagrass on the exposed rocky shores of the Korean peninsula. Many surfgrass meadows on the coasts of Korea have been adversely affected by anthropogenic activities and natural phenomena such as “rock whitening,” which is caused by overgrowths of crustose coralline algae. Few attempts have been made to develop transplanting techniques for surfgrass, owing to the difficulty of transplant survival on exposed rocky shores. We developed a new Phyllospadix Transplant System (PTS), which was an artificial underwater structure constructed of a 4:5:1 ratio of cement, sand, and water. In January 2005, we transplanted P. japonicus shoots using the newly developed PTS. P. japonicus shoots were tied together at the lower part of the sheaths to iron screws, which were placed in a hollow part of the PTS, with latex elastic. To evaluate the feasibility of this transplantation technique, we compared vegetative and reproductive shoot densities, growth, and morphological characteristics in transplants to those of shoots in nearby natural beds over a 2-year period. Transplant density increased gradually without significant initial shoot loss. Approximately 6 months after transplantation, leaf growth of transplants was similar to that of naturally growing shoots. The shoot heights and sheath lengths of transplants were similar to those of naturally growing shoots at 10–15 months post-planting. Approximately 50 mm of rhizome elongation was detected in P. japonicus transplants over the 2-year period. Since P. japonicus transplants attached to the PTS successfully established at the test area, the transplantation of surfgrass using the PTS may be an effective approach to restoring the habitat of P. japonicus .

Seagrass meadows are important biogenic habitats for a wide variety of marine animals and plants, a source of organic carbon for commercially important animals, and act as a nutrient filter in estuarine and coastal ecosystems. As such, mapping the distribution of seagrass beds provides us with an important component of management and conservation strategies. To survey seagrass distribution within Deukryang Bay, we directly observed seagrass beds using SCUBA in Boseong-gun, Goheung-gun, and Jangheung-gun. Seagrass distribution in Geogeum and Gumdang islands were not observed. Specifically, we monitored the distribution area, species composition, morphology, density, and biomass of seagrass meadows. Seagarss beds were mapped for Daikum-ri coast, Deukryang island, Yongjeong-ri coast, Samsan-ri coast and Ongam-ri coast. Total seagrass coverage in Deukryang Bay was , of which was Zostera marina, Z. caulescence and Z. japonica. Z. japonica was found in intertidal zones, Z. marina was found from the intertidal to subtidal zones of 2 m MSL (mean sea level) depth, and Z. caulescence was found in subtidal zones of 2.5-5 m MSL.

The surfgrass Phyllospadix japonicus is endemic to exposed shores of the northeastern Pacific Ocean. Unlike the majority of seagrasses, P. japonicus grows on rocky substrata. The specific physical features of the habitat are likely related to the peculiar ecological characteristics of P. japonicus. However, few studies have been conducted thus far on the growth dynamics of Phyllospadix spp., largely due to the turbulent water conditions in its habitat. P. japonicus is a dominant seagrass species, and it plays critical ecological roles on the eastern coast of Korea. Here, we examined its growth dynamics for the first time on the Korean coast. We measured shoot density, biomass, leaf production, phenology, morphology, tissue nutrient content, as well as environmental factors including underwater photon flux density (PFD), water temperature and water column nutrient concentrations from March 2003 to December 2005. Shoot density, biomass, leaf productivity and morphological characteristics exhibited significant seasonal variations; maximum values of these variables occurred in winter and early spring, and the minima were recorded in late summer and early fall. PFD and water temperature were, respectively, positively and negatively correlated with leaf production. Nutrient availability fluctuated substantially, but there was no evidence of distinct seasonal variation, nor was it correlated with leaf production. Leaf chlorophyll concentrations were correlated strongly with leaf production, whereas tissue nutrient contents were unrelated to leaf production. Maximum potential seed production ranged from 1,200 seeds m−2 in 2004 to 3,445 seeds m−2 in 2003; however, seedlings were rarely detected through the observation period. Thus, P. japonicus meadows at the study site appeared to persist through vegetative propagation. Leaf C content varied bimodally, with peaks in spring and fall. Leaf N content was minimal during months in which leaf productivity was lowest. These patterns in tissue nutrient content are clearly different from those of the majority of soft-substratum seagrasses and appear to relate to the reduced physiological tolerance of high temperature in P. japonicus compared to other temperate seagrasses.

Eight temperate seagrass species (five in the genus Zostera, two in the genus Phyllospadix, and Ruppia maritima) have been previously reported in coastal waters off the Korean peninsula, which lies between 33°N and 43°N. Recently, a species of Halophila, a genus which occurs predominantly in tropical and subtropical areas, has been observed on the southern coast of Korea for the first time. The species was identified as Halophila nipponica. H. nipponica is distributed in warm temperate regions of Japan influenced by the warm Tsushima Current and was previously unknown outside the Japanese archipelago. Thus, we are able to report a range extension into Korea. The Korean Halophila meadow that we observed covered an area of about 2.1 ha, with average shoot density of about 1300 m−2. We measured morphological features of vegetative and reproductive organs between June and September 2007. Morphological and reproductive features of the Halophila species in Korea were similar to those of the species in Japan. Increased water temperature in the coastal waters of Korea may at least partially account for the persistence of this new population.

Significant declines in seagrass coverage have occurred in many parts of the world. In recent decades, transplanting projects for seagrass restoration at die-off areas have been attempted, but most current seagrass transplanting techniques are cost and labor intensive. We have developed a new seagrass transplanting method in which oyster shells are used as an anchoring device, and does not require SCUBA diving for sub-tidal planting. Here, we tested the shell method for feasibility and efficiency in large-scale seagrass restoration. Planting units consisting of two Zostera marina shoots anchored to one oyster shell were dropped from a boat to settle on the sediment at the test site. Four transplanting trials were conducted throughout the experimental period (December 2003, January, February, and November 2004) in Koje Bay on the southern coast of Korea. Eelgrass shoots planted using the shell method successfully established at the test areas, and the survival rates of transplants were comparable to those obtained using other common planting techniques. The transplant shoot density declined during the first 2-3 months following transplantation due to the initial transplant shock, and then surviving shoots became established at the sites and produced new lateral shoots after these periods. Plant size and leaf productivity of transplants 7 months post-transplanting were similar to or exceeded those of pre-existed shoots, suggesting that the physiological status of transplants is similar to that of natural population after 7 months. Because the shell method did not require workers to be in the water, the method was cost and labor effective. Additionally, given that shells originate from marine environments, the shell method did not leave any hazardous materials in the transplanting areas after restoration.

Harmful microalgal blooms such as red-tide or brown-tide events lead to abrupt light reductions and consequently cause immediate damage to seagrass beds. Because red tide algal blooms usually occur unexpectedly, seagrass responses to the microalgal blooms have rarely been documented. A red tide caused by a dense bloom of Heterosigma akashiwo, a noxious red-tide-caus- ing alga of temperate and subtropical waters, occurred at a study site on the south coast of Korea in late May 2002. Because the red-tide event occurred on an eelgrass bed where seagrass monitoring was being conducted, pre-event conditions were well documented. Nearly all eelgrass shoots disap- peared rapidly because of the reduction in light caused by the algal bloom. Additionally, a thick layer of mucilaginous material secreted from algal cysts suffocated eelgrass plants for weeks, directly caus- ing eelgrass death. Eelgrass seedlings were found in the die-off area from December 2002

Seagrass bed is an important component in coastal and estuarine ecosystems, providing food and habitats to a wide variety of marine organisms. Recently, seagrass coverage has declined significantly due to anthropogenic impacts such as cultural eutrophication and reclamation, and thus efforts are under way to prevent further losses and restore disturbed seagrass habitats worldwide. Seagrass transplantation techniques for habitat restoration include vegetative and seed-based methods. Seagrass seeds can be collected easily, and sowing seeds is an economically effective method for large-scale restoration. However, large numbers of seed can be lost by seed predation and physical disturbance in the planting areas. In the present study, Zostera marina seeds were coated with loess to reduce seed loss by predation and sweeping away by the water currents, and germination rates of coated seeds and seedling growth were examined to assess the feasibility of the seed-coating method for large-scale restoration. Germination rate of the coated seeds with loess was significantly higher than that of the uncoated seeds. Additionally, seedling growths were not significantly different between the coated and the uncoated seeds. These results suggest that coating of eelgrass seeds with loess enhances success of seed germintion with no harmful effects on seedling growth. Therefore, the seed coating method using loess may be an effective and applicable seedbased transplanting technique for large-scale restoration.

Production dynamics of eelgrass, Zostera marina was examined in Jindong Bay on the south of the Korea peninsula. Eelgrass leaf productivities and environmental factors such as underwater photon flux density, water temperature, and nutrient availabilities in the water column and sediments were monitored from March 2002 to December 2003. While water temperature exhibited a distinct seasonal trend, underwater irradiance and nutrient availabilities exhibited high degree of fluctuation, and did not show a seasonal trend throughout the experimental periods. Eelgrass leaf elongation and production rates showed significant seasonal variations. Leaf productivity was highest in May (30.0 mg dry wt sht d or 3.7g dry wt md) and lowest in November (3.2 mg dry wt sht d or 0.12 g dry wt m d). Eelgrass leaf productivities did not show a strong correlation with underwater irradiance or environmental nutrient availabilities. The production rates, however, were positively correlated with water temperature during spring periods, and were correlated negatively at high water temperature exceeded 20℃ during summer months. While relative growth rates were highest in spring and lowest in high water temperature periods, plastochrone interval was longest during summer and shortest during spring. These results imply that seasonal growth dynamics of eelgrass, Z. marina was mainly controlled by water temperature.

The growth dynamics of two co-occurring seagrass species, Zostera marina and Halophila nipponica, were examined on the southern coast of the Korean peninsula. Zostera marina is a native dominant seagrass species in Korean coastal waters, whereas H. nipponica is a non-native tropical and subtropical species that has extended its distributional range to the temperate coastal areas of Korea. To examine the differences in the growth dynamics of H. nipponica and Z. marina, their morphology, density, productivity and biomass, as well as local environmental conditions, were monitored monthly from January 2008 to July 2009. Underwater irradiance at the study site was the highest in April 2009 and the lowest in January 2008. Water temperature ranged from 10.4°C in January 2009 to 24.8°C in September 2008. Significant differences in growth dynamics were observed between the species, due to the effect of water temperature at the study site. Density and areal productivity were the highest in April 2008 and June 2008, respectively, for Z. marina but the highest in July 2008 for H. nipponica. Leaf size, shoot height and shoot weight were the highest in July 2008 for Z. marina but the highest in August 2008 or September 2008 for H. nipponica. The productivity of both species was strongly correlated with water temperature at the study site. However, the productivity of these species was not strongly correlated with underwater irradiance or the nutrient availability of either the water column or sediment pore water. Zostera marina exhibited the ecological characteristics of a temperate seagrass, whereas H. nipponica retained the features of a subtropical/tropical seagrass, even after adapting to the temperate coastal waters of Korea.

Here we report the occurrence of a seagrass species, Halophila nipponica J. Kuo, which was recently collected from Ando-ri, Yeosu-city, Jeollanam-do in Korea. H. nipponica, which was first collected from Japan, is the only Halophila species distributed in temperate regions, and was reported as a new species recently. The new Korean common name of this species, ‘Hae-ho-mal’ was given considering its habitat.