• Title/Summary/Keyword: Organism

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Embryonic Development and Metamorphosis of the Ascidian Halocynthia aurantium (붉은멍게(Halocynthia aurantium)의 배발생과 변태)

  • Kim, Gil Jung
    • Journal of Marine Life Science
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    • v.5 no.2
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    • pp.58-63
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    • 2020
  • The ascidian Halocynthia aurantium (sea peach), which belongs to the phylum Chordata, is thought to be a valuable organism of aquaculture like H. roretzi (sea pineapple), but its biological characteristics such as development and ecology are not well known. In this study, in order to obtain basic data for H. aurantium farming, the development processes of H. aurantium inhabiting the east coast of Gangwon-do were investigated and compared with those of H. roretzi, a related species. As a result, the morphology and developmental stages of the fertilized eggs, embryos and larvae of H. aurantium were very similar to those of H. roretzi. Fertilized eggs of H. aurantium took about 42.1 hours to hatch at 11℃, almost similar to 40.9 hours of H. roretzi. The time required for larvae to metamorphose into juveniles after hatching was very similar between the two species. The hatched larvae of the two species became juveniles with oral and atrial siphons after 23 days at 11℃. Both types of embryos developed slowly in seawater at low temperatures and rapidly developed at high temperatures. Fertilized eggs of H. aurantium hatched in an average of 62.3 hours at 9℃, 42.1 hours at 11℃, and 36.3 hours at 13℃, whereas those of H. roretzi hatched in an average of 60.4 hours, 40.9 hours, and 35.2 hours. Most of H. aurantium embryos did not develop normally above 15℃, so it is thought that attention is needed in the seed production processes.

Characteristics of Macro Benthic Community in the Subtidal Zone of Muan Bay on Summer and Health Assessment by using AZTI Marine Biotic Index (AMBI) and Water Quality Index (WQI) (하계 무안만 조하대 저서동물군집 특성 및 AZTI의 해양생물지수(AMBI)와 수질평가지수(WQI)를 이용한 건강성 평가)

  • Oh, Jun Ho;Lee, Kyoung Seon
    • Journal of Marine Life Science
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    • v.7 no.1
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    • pp.21-28
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    • 2022
  • Benthic animals are important indicators in benthic environmental quality assessment. This study investigated the environmental characteristics and the distribution pattern of benthic animals, and assessed the benthic ecosystem using AMBI (AZTI's marine biotic index) and WQI (water quality index) in the subtidal zone of Muan bay. Samplings were collected from 10 stations in the subtidal zone of Muan bay on summer. In the upper area of Muan bay, grain size was finer and organic content was higher than those of in the lower area. The pollution indicator organism such as Musculista senhousia, Theora fragilis and Lumbrineris longifolia were dominant at some stations. The benthic community was distinguished into three groups of upper, center and lower area of Muan bay, and which were coincided with the results by correlation analysis between organic matter content and benthic health assessment (WQI and AMBI). As a result of this study, the health condition of the subtidal zone in Muan bay were good. However, from the results that benthic animals were not evenly distributed, and also the opportunistic species appeared, the load of organic matter in Muan bay seems to be increasing.

Toxicological Assessment to Environmental Stressors Using Exoskeleton Surface Roughness in Macrophthalmus japonicus: New Approach for an Integrated End-point Development (칠게 외골격 표면 거칠기를 이용한 노출 독성 평가: 새로운 융합적 연구)

  • Park, Kiyun;Kwak, Ihn-Sil
    • Korean Journal of Ecology and Environment
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    • v.54 no.4
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    • pp.265-271
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    • 2021
  • Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.

The Effects of Field Trip Learning Program on Plant Inquiry in Coastal Dune using Artificial Intelligence on the Affective Domain of Gifted Elementary Science Studentt (인공지능을 활용한 해안사구 식물 탐구 프로그램이 초등 과학영재의 정의적 영역에 미치는 영향)

  • Byeon, Jung-Ho
    • Journal of Science Education
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    • v.46 no.1
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    • pp.53-65
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    • 2022
  • In the application and composition of learning content, the field trip learning of scientific inquiry could provide a positive effect. Also, it can arouse an experience of various inquiry activities through open thinking. In addition, it could take a positive effect by providing the diversity and specificity of wildlife experience for the living organism. The biology inquiry program of the field trip is a necessary process to acquire ecological experiences in the learning context. However, there is some problem to solve before the performance of field trip learning as professional knowledge of the outdoors inquiry. Therefore, this study developed a field trip inquiry program for the plant in a coastal dune using artificial intelligence to assist professional knowledge. The researcher carried out literature reviews and analysis related to studies and programs to investigate learning steps, content, and strategy. Also, this study investigated the effects of the program on the affective domain of gifted elementary science students. According to the results of this study, the program can provide a positive effect on motivation, task commitment, and attitude level. Consequently, the field trip learning program for plant in the coastal dune using artificial intelligence developed in this study can arouse a positive effect on the affective domain. Therefore, additional study is necessary related to inquiry programs of the field trip for various students and sites.

Exploring life in a public welfare housing for older adults using Stake's case study methodology (Stake식 질적 사례연구 방법을 통해 살펴본 어느 공공 노인복지주택에서의 삶에 관한 연구)

  • Kim, Yujin
    • 한국노년학
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    • v.40 no.1
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    • pp.51-72
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    • 2020
  • The purpose of this study is to understand the experiences of older adults living in the public welfare housing for the elderly and to examine what kind of this housing is as the housing alternative. Through the Robert Stake's intrinsic case study, it explored how older residents experienced this place, and how the relationships between residents, office workers, and community had been in the process, and what kind of issues were there. Various kinds of data, such as resident surveys, participant observations, interviews with 76 elderly residents and 4 office workers, and related newspaper articles, were analyzed using the thematic analysis method and methods suggested by Stake(1995). The results are presented as follows. First, it looked at who lived here and explored what was happening in this place where people of various backgrounds were gathered. Second, four types of life could be seen centering on the social relationship and daily life of older adults. Third, this study examined how the various ways of life were related to the main reasons for moving in here, and summarized how the residents perceived this place. The fourth and the fifth examined the relationships and dynamics among older residents, with office workers, and with the community, focusing on the two issues most commonly mentioned by residents. The results of this study show that, as a living organism, the interaction between the systems affects not only the culture of the housing, but also the lives of older adults. In particular, it can be seen how the perceptions of the practitioners are affecting the lives of the elderly. Based on the results of the study, further considerations were discussed.

Governance Strategy for Marine Microplastic Risk Assessment based on Ecosystem Protection (해양생태계 보호 기반의 해양 미세플라스틱 위해성평가 전략)

  • Jee-Hyun Jung;Won Joon Shim;Moonkoo Kim
    • Journal of Marine Life Science
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    • v.8 no.1
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    • pp.87-92
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    • 2023
  • Microplastic particles are ubiquitous in the environment and not standardized particles of size, shape, or type. Therefore, it is very limited to establish a risk assessment framework that accurately evaluated and manage the multi-dimension of marine environment including seawater and sediment based on toxic data. In the study, we review the characteristics and effects of marine environmental microplastic and suggest risk assessment framework (draft) based on the distribution and impact of marine environmental microplastics. Although, the characteristics of environmental microplastic are very widely but the most abundant toxic data are concentrated on unique shape and type, and there are also large gaps of test organism between laboratory-exposed organisms and resident species. Great limitations with respect to toxicity data quality also exist for traditional effect assessment methods, which in reliability of the resulting risk characterizations. However, considering the fact that the international community's movement on microplastics management is gradually strengthening and the pollution level of microplastics in marine environment is increasing, further research on environmental relevant risk assessment technique should be proposed based on the characteristics of microplastics in the marine environment.

Site Suitability Assessment Using the Habitat Suitability Index for Oyster (Crassostrea gigas) in Jaran Bay, Korea (서식지 적합 지수를 이용한 자란만 굴(Crassostrea gigas)의 어장적지평가)

  • Yong-Hyeon Choi;Sok Jin Hong;Dae In Lee;Won Chan Lee;Seung Ryul Zeon;Yoon-Sik Cho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.5
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    • pp.427-434
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    • 2023
  • Oysters are an important organism, accounting for an average of 76% of shellfish aquaculture production. In this study, optimal habitat was searched for by calculating the Habitat Suitability Index (HSI) using water temperature, salinity, hydrodynamics, DO, SS and Chl.a in Jaran Bay. As a result, the inside of Jaran Bay was found to be a more suitable habitat than the outside with a wide entrance and rapid hydrodynamics. Oyster production and HSI showed a significant correlation (0.710, p<0.05). Hydrodynamics helps the growth of aquaculture organisms, such as food supply through seawater exchange in the bay, which showed a high correlation (0.709, p<0.05) with oyster production. It was found to have a greater effect on habitat suitability than Chl.a. The results of this study are expected to be helpful for the efficient conservation, use and management of coastal fisheries.

A Selection Methodology of the Appropriate Candidate Sites of Riverine Wetlands for Ecological Connection (생태축 연결을 고려한 하천습지의 적정 후보지 선정 방안)

  • Yujin Kang;Won-joon Wang;Haneul Lee;Junhyeong, Lee;Seungmin Lee;Hung Soo Kim
    • Journal of Wetlands Research
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    • v.25 no.2
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    • pp.111-120
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    • 2023
  • In Korea, wetland policies are currently being pursued through long-term plans such as nationwide wetland surveys and wetland conservation basic plans. However, most policies focus on understanding the status of wetlands, such as their area, distribution, and biodiversity, and there is a lack of awareness regarding the need to conserve and manage wetland ecosystems as a single organism. Therefore, this study aims to identify potential riverine wetland sites that can be ecologically connected by considering functional aspects such as floodplain, biodiversity, habitat provision, and tourism resources. This study attempted to select a candidate site that could potentially provide ecological connectivity with three wetlands in the Nakdonggang River water system : Upo Wetland, Hwapocheon Wetland, and Junam Reservoir. 63 wetlands and 7 candidate sites located in 15 subwatersheds of the Nakdonggang River were analyzed, and the most suitable candidate site for ecological connectivity was selected based on the calculated scores. A suitability analysis was conducted using 9 evaluation factors to evaluate candidate sites, and the scoring method, using quantile, was applied to these factors. As a result, Upo2(Hopo) was selected as the most suitable site for ecological connectivity, receiving the highest score 36. Therefore, it is believed that Upo2(Hopo) can serve as a floodplain, habitat, biodiversity enhancer, and tourism resource while being the most suitable for ecological connectivity.

Monoclonal antibody production for CP4 EPSPS detection assays (CP4 EPSPS 검출을 위한 단클론 항체 생산)

  • A-Mi Yoon;Il Ryong Kim;Wonkyun Choi
    • Korean Journal of Environmental Biology
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    • v.39 no.4
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    • pp.445-451
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    • 2021
  • In this study, we described the production of an antibody to living modified organisms (LMOs) containing the gene encoding for 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Agrobacterium tumefaciens strain CP4 EPSPS provides resistance to the herbicide glyphosate (N- (phosphonomethyl) glycine). These LMOs were approved and have recently been used in the feed, food production, and processing industries in South Korea. Highly efficient monoclonal antibody (mAb) production is crucial for developing assays that enable the proper detection and quantification of the CP4 EPSPS protein in LMOs. This study describes the purification and characterization of recombinant CP4 EPSPS protein in E. coli BL21 (DE3) based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrixassisted laser desorption/ionization time-of-flight mass spectrometry. The production of mAbs was undertaken based on the standard operating procedure of Abclon, Inc.(South Korea), and the purity of the mAbs was assessed using SDS-PAGE. The following five mAb clones were produced: 2F2, 4B9, 6C11, 10A9, and 10G9. To verify the efficiency and specificity of the five developed mAbs, we performed Western blotting analysis using the LM (living modified) cotton crude extracts. All mAbs could detect the CP4 EPSPS protein in the LM cotton traits MON1445 and MON88913 with high specificity, but not in any other LM cottons or non-LM cottons. These data indicate that these five mAbs to CP4 EPSPS could be successfully used for the further development of antibody-based detection methods to target CP4 EPSPS protein in LMOs.

Exploring the nature and direction of early childhood science education for sustainable development (지속가능발전지향 유아과학교육의 본질과 실천방향 탐색)

  • Cho, BooKyung;Seo, Hyunjung
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.8 no.3
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    • pp.407-418
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    • 2018
  • Science and technology have led the development of mankind, but have created problems such as natural depletion, climate change, economic inequality and poverty. The purpose of this study is to explore the meaning of early childhood science for sustainable development to solve these problems and to contribute to the harmony of nature and human beings. In order to accomplish this research objectives, 18 experts and 15 teachers were interviewed on the meaning of sustainable development and the directions of early childhood science education for sustainable development. Early childhood science education for sustainable development was categorized as follows. 'Mutual respect between child-teacher-organism', 'developing individual inquiry-based on community consciousness', 'looking at the world with child's eyes', 'deepening and expanding on topics of interest', 'continuous inquiry and commitment', 'conversation and sharing-centered exploration'. By these results, it was concluded that early childhood science education for sustainable development should start from the perspective of children, and was a meaningful process in which children constantly learn about the nature surrounding themselves based on mutual respect.