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Apache Arrow 기반의 인메모리 분산 컴퓨팅을 이용한 고용량 위성 AIS 데이터 처리 및 분석
No full text위성 기반 자동식별시스템(AIS) 데이터는 선박 운항 행태 분석과 해양 교통 연구에 필수적인 정보이지만, 수 십, 수 백 GB에 달하는 대용량, 고빈도 특성으로 인해 단일 컴퓨터 장비로는 빠르게 처리, 분석하는 것은 불가능하다. 본 연구에서는 4.5억 건이 넘는 황해(Yellow Sea) 지역의 위성 AIS데이터를 대상으로 Apache Arrow 기반의 인메모리 분산 및 병렬 처리 기법을 적용하여 고용량 데이터 처리 성능을 획기적으로 향상시키는 방법을 제안한다. 특히, parquet 파일 포맷 기반의 데이터 파티셔닝 및 병렬 연산, 컬럼 데이터 형식 및 메타정보 접근 방식 등을 통해 처리 지연을 최소화 하고, 메모리 상에서 객체 단위 연산을 수행함으로써 기존 파일 기반 접근 방식의 병목 현상을 극복하였다. Apache Arrow는 빅데이터 처리 기술로 가장 유명한 아파치 하둡, 스파크의 분산, 병렬 처리, 인메모리 컴퓨팅 메커니즘과 유사하다고 볼 수 있다. 이를 통해 PC나 노트북의 물리적인 메모리 보다 큰 고용량 데이터를 빠른 속도로 전처리 및 추출, 집계할 수 있으며 처리된 결과는 오픈소스 R, Python 등의 환경에서 즉각 시각화 및 통계 분석이 가능하다. 본 연구는 고용량 위성 AIS 데이터의 빠른 처리와 분석 사례를 소개함으로써 새로운 프레임워크를 제시하고자 하며, 고용량 해양데이터를 원활하게 처리할 수 있는 유용한 오픈소스 솔루션이 될 수 있을 것으로 기대된다.2
Changes in Melatonin and Dopamine Secretion During Ovarian Development in Japanese Eel
No full textIn the present study, we investigated the intricate mechanisms governing the reproductive physiology of female Japanese eels. By investigating the effects of weekly intraperitoneal injections of salmon pituitary extract on the gonadosomatic index and expression levels of reproduction-associated genes, including gnrh1, fsh beta, lh beta, and aromatase (cyp19a), we elucidated the key processes underlying ovarian development and steroidogenesis. Our results demonstrated induced ovarian development at stages 1-4, accompanied by distinct transcriptional profiles in the brain, pituitary gland, and ovary. Notably, gnrh1 exhibited increased expression toward stage 3 in the brain, suggesting a potential role in regulating vitellogenesis, whereas fsh beta and lh beta mRNA levels peaked during stages 2 and 3, respectively, highlighting their significance in ovarian growth. Furthermore, we observed a significant increase in estradiol (E2) levels from stages 2 to 3 of vitellogenesis, which stabilized at stage 4. This trend in E2 levels underscores the pivotal role of this hormone in supporting oocyte development during mid-vitellogenesis and indicates that a carefully regulated hormonal environment is necessary for successful ovarian maturation. A notable surge in cyp19a expression during mid-vitellogenesis underscores the crucial role of cyp19a in estrogen synthesis. Additionally, we observed significant variations in melatonin and dopamine levels in blood plasma, suggesting potential regulatory roles in eel reproduction. These findings deepen our understanding of the complex interplay between endocrine factors and environmental cues in shaping the reproductive strategies of Japanese eel and lay the groundwork for further research.11Nsciescopuskc
Algicidal effects of Fictibacillus sp. 5A8M on Margalefidinium polykrikoides through attachment and secretion of extracellular metabolites
No full textMargalefidinium polykrikoides blooms inflict significant economic losses on the aquaculture industry. Utilizing algicidal bacteria to mitigate harmful algal blooms (HABs) has emerged as an environment-friendly approach. Despite numerous reports on algicidal bacteria, few studies have thoroughly elucidated their mechanisms against M. polykrikoides. In this study, we present the first documentation of the algicidal effect of a Fictibacillus strain on M. polykrikoides. Strain 5A8M exhibited algicidal effects through physical attachment and the secretion of extracellular algicidal metabolites. The algicidal activity of strain 5A8M was dose- and time-dependent. When inoculated at a ratio of 10 % (v/v), strain 5A8M induced lysis in 97.9 % of M. polykrikoides after 24 h of co-culture. The active chlorophyll-a and transcriptional levels of key genes in M. polykrikoides decreased under the algicidal influence of strain 5A8M. Furthermore, exposure to the cell-free filtrate of strain 5A8M for 12 h triggered lipid peroxidation in M. polykrikoides, resulting in elevated malondialdehyde levels. Analysis via 1H nuclear magnetic resonance (NMR), 13C NMR, and electrospray ionization-mass spectra identified l-phenylalanine and anthranilic acid as the extracellular algicidal metabolites produced by strain 5A8M. The algicidal activity of l-phenylalanine and anthranilic acid (10 μg/ml) against M. polykrikoides reached 74.6 and 72.5 %, respectively, within 24 h of exposure. Collectively, our findings underscore the considerable potential of strain 5A8M in controlling M. polykrikoides HABs.11Nsciescopu
Simultaneous Isolation and Preparation of Extracellular Vesicles by Circular Multicavity Electrophoresis
No full textExtracellular vesicles (EVs) play a crucial role in diagnosis and treatment, yet obtaining highly purified EVs from complex biological samples is often hindered by nanoscale contaminants. In this work, considering the charge-to-size characteristics of EVs, a circular multicavity electrophoresis (CME) with gradient pore size distribution was constructed in the gradient electric field to realize the isolation and preparation of EVs. By the gradient gel sieving effect, small cell debris, EVs, and proteins in biological samples were gradually separated. The integration of ultrafiltration (UF) with CME synergistically enhances EV purification and preparation, resulting in a purity level 3.15 times higher than that achieved through ultracentrifugation (UC). The high yield preparation of EV was achieved through continuous injection facilitated by the application of a gradient electric field, where 3.55 x 1010 +/- 6.32 x 108 particle numbers mL-1 of EVs were prepared from 36 mL of cell supernatant, and the recovery approached 87.65 +/- 9.03%. Further evaluation of the cell uptake efficiency of EVs derived from umbilical cord mesenchymal stem cells prepared by CME-UF revealed that this approach effectively preserves both the integrity and bioactivity of the EVs. This work presents a novel approach for the isolation and preparation of EVs, offering valuable insights into future biological studies.11Nsciescopu
Multi-source hydrothermal mineralisation in the ultramafic-hosted Mirae-2 vent field, Central Indian Ridge
No full textModern seafloor massive sulfide deposits distributed along mid-ocean ridges are typically classified as mid-ocean ridge basalt- and ultramafic-hosted types, based on mineralogical and geochemical characteristics that result from the different water-rock interactions between the two substrates. However, the Mirae-2 vent field (MVF-2) along Central Indian Ridge, which was newly discovered on the slope of an oceanic core complex, deviates from this common concept. Mineralogical and geochemical data indicate that the formation of chimney and mound samples was primarily controlled by changes in physicochemical fluid conditions (temperature, pH, & fnof;S-2, and & fnof;O-2) driven by varying degrees of fluid-seawater mixing. In particular, the prevalence of sulfide assemblages (pyrrhotite + isocubanite + Fe-rich sphalerite), the Cu-Au-rich mineralisation, and the enrichments of Co (average = 1109 ppm) and Sn (203 ppm) are similar to those of other ultramafic-hosted sulfide deposits, but the high amounts of barite and galena, and the enrichments of Ba (> 100,000 ppm) and Pb (up to 8.91 wt%) reflect the contribution of distinct metal sources other than ultramafic substrates. The extremely positive delta S-34 values of pyrite (average = + 15.1 +/- 1.7 parts per thousand) and pyrrhotite (+ 6.37 +/- 0.5 parts per thousand) indicate that metals and S in the MVF-2 were likely derived from serpentinised ultramafic rocks with intense mixing of fluids with seawater, whereas the unusually radiogenic Pb isotope ratios of sphalerite (Pb-206/Pb-204 = 18.531-18.559, Pb-207/Pb-204 = 15.540-15.564, and Pb-208/Pb-204 = 38.632-38.693) suggest that the enriched mid-ocean ridge basalts (i.e., MVF-2 basalts) near the ridge axis also had an important role in the supply of some metals (Pb and Ba) to the MVF-2 fluids. Our results indicate that the multi-stage fluid-rock reactions with basalt and subsequent ultramafic rocks produced the multi-source hydrothermal fluids, thereby resulting in the different mineralogy and geochemistry of the MVF-2 compared with other ultramafic-hosted sulfide deposits.11Nsciescopu
Biogeography and Biodiversity of Hydrothermal Vent Fauna along the Central Indian Ridge
No full textThe Central Indian Ridge (CIR) is located between the Carlsberg Ridge and the Rodrigues Triple Junction. Its central location makes the CIR optimal for studying the biogeographic connectivity of hydrothermal vent fauna across the Mid-Indian Ridge (MIR). In this study, we analyzed the biogeography and biodiversity of hydrothermal vent communities using imagery from seven active vent fields along the CIR: Onbada, Onnare, Onnuri, and Saero (northern CIR; nCIR), Cheoeum, Mirae-2, and Maru (southern CIR; sCIR). Video and still images were acquired using the Remotely Operated Vehicle (ROV) ROPOS from 2021 to 2024. The megafauna observed in the images were analyzed to the lowest possible level by comparing them with the morphological and genetic analysis results of the collected specimens. Our findings revealed notable differences in vent fauna between the nCIR and sCIR. The sCIR demonstrated relatively lower diversity, with a prevalence of Rimicaris shrimps. Additionally, the sCIR exhibited a total absence or scarcity of Bathymodiolus mussels and Alviniconcha snails. In the sCIR, mussels and juvenile snails were observed at Cheoeum, only juvenile snails at Mirae-2, and neither at Maru. This suggests that the hydrothermal vents in the nCIR could be more mature and well-established environments in comparison to those in the sCIR. Alternatively, dispersal barriers between the nCIR and the sCIR may result in the distinct biogeography and biodiversity of vent fauna along the CIR. These findings emphasize the necessity for continued and detailed exploration of the hydrothermal vent fauna in the CIR to enhance our understanding of the biogeography and biodiversity of hydrothermal vent fauna along the MIR.1
Nitrogen Source Preferences and Ecological Implications of Phytoplankton Primary Production in the Yellow Sea, South Sea of Korea, and East/Japan Sea, 2018
No full textUnderstanding the partitioning of primary production into new and regenerated productions, based on nitrate or ammonium utilization, is crucial to understanding biogeochemical processes and marine ecosystems. This study addresses the scarcity of information on new and regenerated productions in the Yellow Sea (YS), South Sea (SS), and East/Japan Sea (EJS). Employing the 13C–15N tracer method, we quantified carbon and nitrogen uptake rates of phytoplankton across four seasons in 2018. Seasonal nitrate and ammonium uptake rates exhibited distinct ranges in the YS (0.2–6.1 and 0.4–22.3 mg N m−2 hr−1), SS (1.0–15.6 and 4.5–15.4 mg N m−2 hr−1), and EJS (1.5–7.3 and 4.5–15.4 mg N m−2 hr−1). Notably, nitrate uptake rates in the YS (except spring), SS, and EJS were generally lower than ammonium uptake rates, attributed to the dominance of pico-sized (<2 μm) phytoplankton with a high affinity for ammonium. Carbon uptake rates in all seas displayed significant positive correlations with nitrate uptakes rather than ammonium uptakes, suggesting that the prevailing ammonium assimilations by dominant pico-sized phytoplankton contributed to the lower primary productions in 2018. Estimated annual new productions (30, 24, and 43 g C m−2 y−1) in the YS, SS, and EJS fall within the reported ranges for other regions. However, the EJS exhibited lower productions than previous reports (146 g C m−2 y−1), potentially impacting fishery yields and export production to the deep ocean in 2018. These findings, in the context of rapid environmental changes, provide crucial baseline information for monitoring future marine ecosystems in Korean seas.11Nsciescopu
Chromatographic purification of stable isotopes of Ni, Cu, and Zn and their isotopic compositions in geological and biological reference materials
No full textNickel (Ni), copper (Cu), and zinc (Zn) isotopes are used to study biogeochemical and environmental processes. Studies using multiple metallic isotopes are being conducted to advance knowledge of many processes in the Earth system. However, most chromatographic purification methods focus on a single element and studies of multiple metals require different chemical separation protocols. In this study, we developed a new three-step sequential chromatographic protocol that enables isotope studies of Ni, Cu, and Zn in a single sample and is applicable to diverse sample types. Isotope compositions were measured by MC-ICP-MS with different sample introduction systems (wet plasma for Cu and Zn; dry plasma for Ni). Instrumental mass bias was corrected by sample-standard bracketing (SSB) and internal doping with an isotope standard of similar mass. The Ni, Cu, and Zn yields were ∼99% for six geological and two biological reference materials. The δ60Ni, δ65Cu, and δ66Zn values measured in this study were consistent with reported data within the analytical uncertainty. New isotope values in reference materials, including rock, mineral resources, soil, sediments, urban dust, sludge, and living organisms, are reported for Ni (n = 44), Cu (n = 24), and Zn (n = 17). This method can produce high-precision isotope data from various environmental samples, even with limited sample amounts. This work presents an improved method over existing approaches, opening potential applications for metallic stable isotopes in various research fields.11Nsciescopu
A legal review of the provisions of the UN BBNJ Agreement on marine bio-research and development
No full text본 논문의 목적은 UN BBNJ 협정상 해양바이오 연구개발 절차의 이해를 돕고, 향후 당사국총회에서 추가적으로 논의되어야 하는 법적 공백을 찾아 우리나라의 향후 대응 방안 제시에 있다. 이를 위하여 제1장에서 해양 바이오 시장의 빠른 성장 추세를 제시하고 왜 UN BBNJ 협정의 해양바이오 연구개발 절차가 우라나라에 큰 의미를 가지는지를 설명하였다. 그리고 제2장에서는 국가관할권 바깥 해역 해양바이오 연구개발에 관련된 UN BBNJ 관련 규정이 어떠한 절차를 설립하였는지 해양바이오 연구개발의 통상 절차에 맞추어 환경영향평가, 통고, 이익공유의 순서로 소개했다. 제3장은 현재 설립된 UN BBNJ 규정에서 미비한 사항들을 역시 환경영향평가, 통고, 이익공유의 순서로 검토해 봤다. 그리고 제4장 결론에서 제1장, 제2장, 제3장에서 전술한 내용을 기반으로 ‘UN BBNJ 협정 시대 대비 해양바이오산업 신성장 전략’을 위한 법･정책적 제언을 하였다.
제2장과 제3장에서는 UN BBNJ 협정 해양바이오 연구개발절차 규정에 대한 법적 분석이 이루어졌는데 그 핵심은 아직 다음과 같은 법적 불명확성과 공백이 남아 있다. 첫째 환경영향평가 규정에서 불확실성은 협정의 통일적인 적용을 저해하고, 제도적 실효성을 약화시킬 우려를 야기한다. 특히, 제29조 제4항의 환경영향평가 예외 조항에서 사용된 “relevant”, “equivalent”, 등 모호한 용어는 당사국의 자의적 해석 가능성을 높이며, 이는 협정 의 실효성을 훼손할 수 있다. 또한, 제30조 제1항의 “사소하거나 일시적인 영향”, “실질적 오염 또는 중대하고 해로운 변화” 등 기준의 부재 역시 당사국에게 과도한 재량권을 부여하여 협정 이행에 혼란을 초래할 수 있다. 통고 규정 역시 해석적 난점을 내포하고 있다. 제12조 제2항의 “현지 내 채집”의 범위와 통고 의무 발생 기준의 불명확성은 통고 절차의 혼란을 야기할 수 있으며, 제12조 제3항의 BBNJ 표준일괄식별자의 개념 및 형태에 대한 규정 미비는 통고 시스템 운영에 심각한 차질을 초래할 수 있다. 더욱이, 제12조 제6항의 디지털 서열 정보의 범위와 현재 국제 실행의 기준에 대한 해석적 불일치는 정보 공유의 균일성을 확보하는 데 어려움을 초래할 수 있다. 제12조 제8항의 “subject to utilization”의 해석 차이는 제3차 통고 의무 발생 시점에 대한 추가적인 지침의 필요성을 시사한다. 이익공유 규정의 불확실성 역시 불확실성을 내포하고 있다. 제14조 제1항의 이익 공유 대상 “활동”의 범위와 “a fair and equitable manner”의 개념에 대한 명확한 정의 부재는 이익 공유 체계의 불확실성을 증폭시킨다. 또한, 제14조 제2항의 “시료와 시료 모음”, “FAIR 과학 데이터”, “개방적이고 책임 있는 데이터 거버넌스” 등 용어의 해석적 난점과 당사국총회의 권능 조항은 협정 이행의 예측 가능성을 저해한다. 제4장에서는 법적 분석에 근거하여 다음과 같은 정책 제안을 하였다. 첫째, 국가관할권 바깥 해역 해양바이오 연구개발 활동에 대한 정부의 장기적 지원과 육성이다. 이는 국가관할권 바깥 해역 해양바이오 연구개발에 필요한 막대한 초기 비용을 고려한 것으로 이 부담을 국가 지원을 통해 감소시켜 해양바이오 산업을 진흥하기 위함이다. 둘째, 해양바이오 산학연 전문가로 구성된 ‘UN BBNJ 해양바이오 전문가 협의체’ 수립이다. 이는 정책결정자가 전문 분야에 대한 의사결정을 과학계의 실행에 부합되게 내릴 수 있도록 지원함과 동시에 이해관계자의 참여를 통하여 절차적 정당성을 확보하는 효과가 있다. 셋째, UN BBNJ 정부간회의 대응에 준하는 수준의 UN BBNJ 당사국총회 대응이다. UN BBNJ 당사국총회는 이제 UN BBNJ의 입법기관으로서 우리 이해관계자에게 직접적 영향을 미치는 입법활동을 수행할 것이므로 과학적 정보와 실행에 기반한 세부 성안을 통하여 현재 연구개발 실행과 UN BBNJ 협정 체제간에 간극이 생겨 연구개발 활동에 불필요한 절차적 경제적 부담이 발생하지 않도록 해야 할 것이다. 마지막으로 가장 중요한 것은 UN BBNJ 협정의 성공적 이행을 위한 기본 메커니즘인 국내 법체제의 수립이다. 상술한 정책 제언은 국내 입법을 통해서만 실체화될 수 있기 때문이다. 국내 입법 과정에서 가장 먼저 고려해야 할 사항은 국가관할권 바깥 해역에서 수행되는 해양바이오 연구개발 활동에 대한 규제와 진흥 사이의 섬세한 균형이다. 그러므로 엄격한 환경보호 의무를 준수하면서도 해양바이오 연구개발의 혁신적 잠재력을 저해하지 않는 균형 잡힌 접근법을 채택하여야 한다. 또한 당사국총회의 지속적인 입법을 탄력적으로 수용하고 이행할 수 있는 법적 대응체제에 대한 사전 설계가 국내 입법제도 안에 구축되어야 할 것이다.22Nkc
Properties of inflowing Pacific and Atlantic water govern total and methylated mercury profiles in the Arctic Ocean
No full textHigh methylmercury (MeHg) concentrations in Arctic marine biota have been linked to high MeHg uptake driven by shallow MeHg peaks at water depths of 100–300 m in the Arctic Ocean. To understand how the biogeochemical characteristics of each basin affects the distribution of total Hg (THg) and MeHg across the Arctic Ocean, the spatial patterns of THg and MeHg were investigated using data from new transects in the Beaufort Sea (BS) and previously published Arctic Ocean expeditions covering the Canada Basin and Makarov Basin in the Pacific sector, and Amundsen Basin and Nansen Basin in the Atlantic sector. In the BS, the THg concentration in the polar mixed water increased with salinity (r = 0.87, p < 0.01), which was linked to THg transport from the Chukchi Shelf. Transport of Hg from the Chukchi Shelf also drove elevated THg concentrations in the polar mixed water and halocline water in the Canada Basin and Makarov Basin compared to other Arctic basins. The MeHg concentration in the BS was positively correlated with the biological index in the Pacific summer water (r = 0.86, p < 0.01), demonstrating that intrusion of warm and nutrient-rich Pacific water promotes MeHg production in the BS. In line with this result, chlorophyll-a showed a comparable cross-basin trend to that of MeHg, with the highest values in the Nansen Basin. In the halocline water, MeHg concentrations were highest in the Canada Basin likely due to the largest availability of Hg(II). On the contrary, MeHg concentration was highest in the Nansen Basin in the Atlantic water layer, which could be related to the higher seawater temperature and enhanced biological production. The results of this study underscore the critical role of Pacific and Atlantic inflows in modulating the profiles of THg and MeHg in the Arctic Ocean.11Nsciescopu