23 research outputs found

    Sulfur assimilation using gaseous carbonyl sulfideby the soil fungus Trichoderma harzianum

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    Fungi have the capacity to assimilate a diverse range of both inorganic and organic sulfur compounds. It has been recognized that all sulfur sources taken up by fungi are in soluble forms. In this study, we present evidence that fungi can utilize gaseous carbonyl sulfide(COS) for the assimilation of a sulfur compound. We found that the filamentousfungus Trichoderma harzianum strain THIF08, which has constitutively high COS-degrading activity, was able to grow with COS as the sole sulfur source. Cultivation with 34S-labeled COS revealed that sulfur atom from COS was incorporated into intracellular metabolites such as glutathione and ergothioneine. COS degradation by strain THIF08, in which as much of the moisture derived from the agar medium as possible was removed, indicated that gaseous COS was taken up directly into the cell. Escherichia coli transformed with a COS hydrolase (COSase) gene, which is clade D of the β-class carbonic anhydrase subfamily enzyme with high specificity for COS but low activity for CO2 hydration, showed that the COSase is involved in COS assimilation. Comparison of sulfur metabolites of strain THIF08 revealed a higher relative abundance of reduced sulfur compounds under the COS-supplemented condition than the sulfate-supplemented condition, suggesting that sulfur assimilation is more energetically efficient with COS than with sulfate because there is no redox change of sulfur. Phylogenetic analysis of the genes encoding COSase, which are distributed in a wide range of fungal taxa, suggests that the common ancestor of Ascomycota, Basidiomycota, and Mucoromycota acquired COSase at about 790-670 Ma. © 2024 Iizuka et al

    Antarctic Study on Tropospheric Aerosol and Snow Chemistry (ASTASC) in JARE Phase X

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    The Tenth Symposium on Polar Science/Special session: [S] Future plan of Antarctic research: Towards phase X of the Japanese Antarctic Research Project (2022-2028) and beyond, Tue. 3 Dec. / Entrance Hall (1st floor) at National Institute of Polar Research (NIPR

    Isotopic evidence for acidity-driven enhancement of sulfate formation after SO2 emission control

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    After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO2) emissions. However, a lack of observational evidence has hindered the identification of causal feedback mechanisms. Here, we report an increase in the oxygen isotopic composition of sulfate (Δ17OSO42-) in a Greenland ice core, implying an enhanced role of acidity-dependent in-cloud oxidation by ozone (up to 17 to 27 in sulfate production since the 1960s. A global chemical transport model reproduces the magnitude of the increase in observed Δ17OSO42- with a 10 to 15 to sulfate in Eastern North America and Western Europe. With an expected continued decrease in atmospheric acidity, this feedback will continue in the future and partially hinder air quality improvements

    Window Shape Estimation for Glass Façade-Cleaning Robot

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    This paper presents an approach to the estimation of a window shape for increasing the adaptability of glass façade-cleaning robots to different buildings. For this approach, a window scanning robot equipped with a 2D laser range scanner installed perpendicularly to a window surface is developed for the testbed, and a method for the window shape estimation is proposed, which consists of the robot’s pose estimation with an extended Kalman filter (EKF) and the loop closure based on the robot’s pose estimated. The effectiveness of the proposed approach is demonstrated through an experiment that is carried out on a window placed on a floor. The experimental results show that the window scanning robot can acquire a window shape, moving on a window surface, and the proposed approach is effective in increasing the accuracy of the window shape estimation

    [Dataset] High flux of small sulfate aerosols during the 1970s reconstructed from the SE-Dome ice core in Greenland

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    Aerosols significantly affect Earth's radiation budget, thus influencing global climate. In the Arctic, sulfate aerosols are thought to have reduced the warming during the twentieth century. However, trends in past sulfate aerosols are poorly known, especially the aerosol sizes and compositions. Here, we analyze a high-resolution ice core from southeastern Greenland, comparing the seasonal deposition flux of large sulfate salt particles and small sulfur compounds, including non-neutralized sulfuric acid, between the anthropogenic sulfate maximum (1973-1975) and after sulfur emissions control (2010-2012). Between these periods, we find that the large-diameter (>0.4 mu m) flux remains roughly unchanged, yet the small-diameter (<0.4 mu m) aerosol flux significantly decreases. The results indicate that small sulfates were efficiently activated as cloud condensation nuclei during the 1970s, and thus likely increased cloud albedo, offsetting the warming
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