1,431 results match your criteria: "Tokyo University of Marine Science and Technology[Affiliation]"

Foams are a ubiquitous feature of marine environments. They can have major economic, societal and ecological consequences through their accumulation on the shore. Despite their pervasive nature and evidence that stable foam deposits play a pivotal role in the ecology of soft shore and estuaries, very limited amounts of information are available on their contribution to the structure and function at play in rocky intertidal ecosystems.

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Fast-sinking zooplankton carcasses and fecal pellets appear to contribute significantly to the vertical transport of particulate organic carbon (POC), partly because of low temperature that decreases microbial degradation during the descent into the deep ocean. Increasing hydrostatic pressure could further reduce the degradation efficiency of sinking POC, but this effect remains unexplored. Here, the degradation of carcasses and fecal pellets of the abundant marine copepod was experimentally studied as a function of pressure (0.

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New polycyclic tetramate macrolactams with antimycobacterial activity produced by marine-derived Streptomyces sp. KKMA-0239.

J Antibiot (Tokyo)

May 2024

Department of Microbial Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.

Article Synopsis
  • Researchers screened for new anti-mycobacterial agents against Mycobacterium avium complex (MAC) and discovered two new compounds called hydroxycapsimycin and brokamycin, along with ikarugamycin.
  • The structures of hydroxycapsimycin and brokamycin were determined using advanced spectroscopic techniques like 1D and 2D NMR.
  • Hydroxycapsimycin's absolute configuration was confirmed through single-crystal X-ray diffraction, while both brokamycin and ikarugamycin showed moderate effectiveness against drug-resistant strains of MAC.
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Spectral analysis of environmental microplastic polyethylene (PE) using average spectra.

Sci Total Environ

June 2024

Faculty of Marine Resources and Environment, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-Ku, Tokyo 108-8477, Japan. Electronic address:

In this study, microplastic samples from surface seawater of Tokyo Bay were collected, polyethylene (PE) microplastics were used to calculate carbonyl index (CI), and average spectra of PE were analyzed and compared with a previous study applying agitation during chemical treatment. It was found that PE and polypropylene (PP) were the predominant polymer type in the samples. Among PE samples, fragments were the most commonly observed shape, with white being the dominant color.

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The tolerance of a keystone ecosystem engineer to extreme heat stress is hampered by microplastic leachates.

Biol Lett

March 2024

Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, IRD, UMR 8187, LOG, Laboratoire d'Océanologie et de Géosciences, Station marine de Wimereux, 59000 Lille, France.

Plastic pollution and ongoing climatic changes exert considerable pressure on coastal ecosystems. Unravelling the combined effects of these two threats is essential to management and conservation actions to reduce the overall environmental risks. We assessed the capacity of a coastal ecosystem engineer, the blue mussel , to cope with various levels of aerial heat stress (20, 25, 30 and 35°C) after an exposure to substances leached from beached and virgin low-density polyethylene pellets.

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Article Synopsis
  • Kuruma shrimp (Penaeus japonicus) adjust their levels of alanine, a free amino acid, to maintain osmotic pressure in response to changes in environmental salinity.
  • The study involved cloning the alanine aminotransferase (ALT) gene, crucial for alanine production, revealing it as a 3,301 bp sequence that encodes a protein of 514 amino acids with conserved activity-related residues.
  • Expression analysis showed that ALT1 mRNA levels in the shrimp significantly increased at higher salinities, particularly at 40‰, indicating its role in boosting alanine concentration in order to manage osmotic balance.
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Kanpyo (KP) is an edible dried product produced by peeling the fruit of the gourd var; it is used in the traditional Japanese cuisine. The health functionality of KP due to its rich dietary fibre is expected to include a possible combined effect of KP-responsive indigenous gut bacteria (KP-RIB). However, its effect on the gut microbiota is unclear.

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Dihydrogen (H) is an important intermediate in anaerobic microbial processes, and concentrations are tightly controlled by thermodynamic limits of consumption and production. However, recent studies reported unusual H accumulation in permeable marine sediments under anoxic conditions, suggesting decoupling of fermentation and sulfate reduction, the dominant respiratory process in anoxic permeable marine sediments. Yet, the extent, prevalence and potential triggers for such H accumulation and decoupling remain unknown.

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Depth perception of stereoscopic transparent stimuli with frame manipulation.

Sci Rep

March 2024

Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, 2 Etchujima, Koto-ku, Tokyo, 135-8533, Japan.

Depth perception is crucial in human vision, allowing us to move and interact with our 3-D surroundings. We used a stereoscopic transparent stimulus comprising parallel overlapping transparent stereoscopic surfaces (POTS) to understand depth perception better. The study focused on exploring the effect of a surrounding frame on the perceived depth of a POTS configuration.

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The digestive organs of terrestrial isopods harbour bacteria of the recently proposed mollicute family . The only complete genome available so far for is that of ' Hepatoplasma crinochetorum'. The scarcity of genome sequences has hampered our understanding of the symbiotic relationship between isopods and mollicutes.

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This paper describes the stabilization of liposomes using a PEGylated lipid, -(methylpolyoxyethylene oxycarbonyl)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine sodium salt (DSPE-PEGs), and the evaluation of the survival rate in natural seawater for future environmental applications. Liposomes in natural seawater were first monitored by confocal microscopy, and the stability was compared among different lengths and the introduction ratio of DSPE-PEGs. The survival rate increased with an increase in the PEG ratio.

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Improved hourly estimate of aerosol optical thickness over Asian land by fusing geostationary satellites Fengyun-4B and Himawari-9.

Sci Total Environ

May 2024

State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.

Article Synopsis
  • - Asian over-land aerosols consist of a mix of human-made pollutants and natural dust, making accurate measurement of aerosol optical thickness (AOT) via satellites vital for effective data assimilation.
  • - A new fusion algorithm was created to estimate optimal AOT over Asia at a fine resolution of 10 km × 10 km from September 2022 to August 2023, improving data accuracy by correcting biases and leveraging high-resolution data from Fengyun-4B and Himawari-9 satellites.
  • - The resulting fused AOT data significantly outperforms original measurements, showing a 40.6% reduction in root mean square error (RMSE) and a 27.8% increase in correlation coefficient (CORR
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Abundance and potential sources of floating polystyrene foam macro- and microplastics around Japan.

Sci Total Environ

May 2024

Training Vessel Kagoshima maru, Faculty of Fisheries, Kagoshima University, 4-50-20 Shimoarata, Kagoshima 890-0056, Japan. Electronic address:

Polystyrene foam is widely used due to its lightweight, impact resistance, and excellent thermal insulation properties. Meanwhile, weak adhesion between beads in polystyrene foam leads to fragmentation, generating a substantial amount of microplastics (<5 mm). Such polystyrene foam debris littered on beaches diminishes the aesthetic value of coastal areas, negatively impacting tourism.

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Seafloor primary production in a changing Arctic Ocean.

Proc Natl Acad Sci U S A

March 2024

Takuvik International Research Laboratory, CNRS/Université Laval, Québec City, QC G1V 0A6, Canada.

Phytoplankton and sea ice algae are traditionally considered to be the main primary producers in the Arctic Ocean. In this Perspective, we explore the importance of benthic primary producers (BPPs) encompassing microalgae, macroalgae, and seagrasses, which represent a poorly quantified source of Arctic marine primary production. Despite scarce observations, models predict that BPPs are widespread, colonizing ~3 million km of the extensive Arctic coastal and shelf seas.

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  • This study focused on the gelation properties and behaviors of Ficus awkeotsang Makino pectin (JFSP) in acidic environments (pH 3.4-4.5), highlighting its ability to form gels without added metal ions.
  • At optimal pH levels (3.75-4.05), JFSP formed strong gel networks with significant stability, influenced by hydrogen bonds, while changes in pH affected the gel's structure and stability.
  • The research offers insights into how JFSP behaves under low acidity, which could benefit future food formulation efforts that require stable gel-like textures in similar conditions.
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Satisfactory separation of milk-derived extracellular vesicles (MEVs) is important for the downstream analysis of the functions and properties of MEVs. However, the presence of abundant proteins in milk hindered the separation of MEVs. In this study, three pretreatment methods, including sodium citrate (SC), acetic acid (AA), and high-speed centrifugation, were adopted to separate MEVs from goat milk while minimizing the impact of protein.

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The number of elements distributed in a three-dimensional stimulus is overestimated compared to a two-dimensional stimulus when both stimuli have the same number of elements. We examined the effect of the properties of a three-dimensional stimulus (the number of overlapping stereo surfaces, size of the elements, and size of the area containing elements, on the overestimation phenomenon in four experiments. The two stimuli were presented side-by-side with the same diameters.

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Background And Aim: Oxygen concentration is an essential water quality parameter for aquaculture systems. Recently, supersaturated dissolved oxygen (DO) has been widely used in aquaculture systems to prevent oxygen depletion; however, the long-term effects of supersaturated DO exposure on aquatic animals have not been studied. In this study, we examined the effects of supersaturated DO on the growth, survival, and gene expression of Pacific white shrimp ().

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Recent advances in reinforced bioplastics for food packaging - A critical review.

Int J Biol Macromol

April 2024

Gdansk University of Technology, Faculty of Civil and Environmental Engineering, Department of Sanitary Engineering, 80 - 233 Gdansk, G. Narutowicza St. 11/12, Poland. Electronic address:

Recently, diversifying the material, method, and application in food packaging has been massively developed to find more environment-friendly materials. However, the mechanical and barrier properties of the bioplastics are major hurdles to expansion in commercial realization. The compositional variation with the inclusion of different fillers could resolve the lacking performance of the bioplastic.

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In this study, extrusion method was employed to fabricate alginate-zein core-shell microcapsules loaded with buckwheat honey by dropping alginate and buckwheat honey mixture solution into a 70.0 % zein ethanol solution(v/v) containing 5.0 % CaCl solution (wt%).

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Microplastics (MPs), small synthetic particles, have emerged as perilous chemical pollutants in aquatic habitats, causing grave concerns about their disruptive effects on ecosystems. The fauna and flora inhabiting these specific environments consume these MPs, unwittingly introducing them into the intricate web of the food chain. In this comprehensive evaluation, the current methods of identifying MPs are amalgamated and their profound impacts on marine and freshwater ecosystems are discussed.

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In marine sediments, microbial degradation of organic matter under anoxic conditions is generally thought to proceed through fermentation to volatile fatty acids, which are then oxidized to CO2 coupled to the reduction of terminal electron acceptors (e.g. nitrate, iron, manganese, and sulfate).

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Phylogenetic evidence suggests a shared ancestry between mitochondria and modern Proteobacteria, a phylum including several genera of intracellular pathogens. Studying these diverse pathogens, particularly during intracellular infection of their hosts, can reveal characteristics potentially representative of the mitochondrial-Proteobacterial ancestor by identifying traits shared with mitochondria. While transcriptomic approaches can provide global insights into intracellular acclimatization by pathogens, they are often limited by excess host RNAs in extracts.

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To assess the blending effect of field snails with grass carp muscle, the effects of paramyosin (PM) and actomyosin (AM) with different mixture ratios on the gel properties of the binary blend system were investigated in our work. The purified PM from field snail muscle was about 95 kDa on SDS-PAGE. Its main secondary structure was α-helix, which reached to 97.

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A new lipopeptide, N-desmethylmajusculamide B (1), was isolated from the Okinawan cyanobacterium Okeania hirsuta along with 2 known compounds majusculamide A (2) and majusculamide B (3). The planar structure of (1) was elucidated by a detailed analysis of mass spectrometry and nuclear magnetic resonance spectra. The absolute configurations of the amino acid residues were determined using Marfey's analysis.

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