arXiv subjects

Satoshi Wada

Publications and source records attributed to Satoshi Wada.

3 recordsLinked to original sources

arXiv2025

Symbiotic causal network of seagrass-bacteria-algae-diatoms interactions

Seagrass meadows contribute to the conservation of marine ecosystems, reduction in global warming impacts and pathogen controls. However, the decline in seagrass habitats due to environmental loads has become an urgent global issue. One way to address this issue is to better understand healthy seagrass habitats. Here, we estimate the structural characteristics of symbiotic and metabolic systems in sediments from eight coastal regions of Japan, with each region containing both seagrass-covered areas and adjacent unvegetated areas. Notably, seagrasses commonly maintain a balanced symbiotic relationship characterized by a positive association with cable bacteria (Desulfobulbaceae), nitrogen-cycling bacteria (Hyphomonadaceae), and coral algae (Corallinophycidae) and a negative association with diatoms (Diatomea). Furthermore, seagrass growth conditions influence metabolic pathways by activating nitrogen-related metabolism while attenuating methanogenesis. Our findings highlight the crucial roles of marine plants and their symbiotic systems in ensuring environmental conservation within the context of blue carbon storage across environmental gradients.

q-bio.QM↗

arXiv2022

Study on the reusability of fluorescent nuclear track detectors using optical bleaching

Fluorescent nuclear track detectors (FNTDs) based on Al${_2}$O${_3}$:C,Mg crystals are luminescent detectors that can be used for dosimetry and detection of charged particles and neutrons. These detectors can be utilised for imaging applications where a reasonably high track density, approximately of the order of 1 $\times$ $10^4$ tracks in an area of 100 $\times$ 100 $\mu$m$^2$, is required. To investigate the reusability of FNTDs for imaging applications, we present an approach to perform optical bleaching under the required track density conditions. The reusability was assessed through seven irradiation-bleaching cycles. For the irradiation, the studied FNTD was exposed to alpha-particles from an $^{241}$Am radioactive source. The optical bleaching was performed by means of ultraviolet laser light with a wavelength of 355 nm. Three dedicated regions on a single FNTD with different accumulated track densities and bleaching conditions were investigated. After every irradiation-bleaching cycle, signal-to-noise ratio was calculated to evaluate FNTD performance. It is concluded that FNTDs can be reused at least seven times for applications where accumulation of a high track density is required.

physics.ins-det↗

arXiv2022

Estimation of symbiotic bacterial structure in a sustainable seagrass ecosystem on recycled management

Seagrass meadows play an essential role in blue carbon and aquatic ecosystem services. However, methods for the flourishing of seagrass are still being explored. Here, data from 49 public coastal surveys on the distribution of seagrass and seaweed around the onshore aquaculture facilities are revalidated, and an exceptional area where the seagrass Zostera marina thrives was found. The bacterial population there showed an apparent decrease in the pathogen candidates belonging to the order Flavobacteriales. Moreover, structure equation modeling and a linear non-Gaussian acyclic model based on the machine learning data estimated an optimal symbiotic bacterial group candidate for seagrass growth as follows: the Lachnospiraceae and Ruminococcaceae families as gut-inhabitant bacteria, Rhodobacteraceae as photosynthetic bacteria, and Desulfobulbaceae as cable bacteria modulating oxygen or nitrate reduction and oxidation of sulfide. These observations confer a novel perspective on the seagrass symbiotic bacterial structures critical for blue carbon and low-pathogenic marine ecosystems in aquaculture.

q-bio.PE↗