Population-level prokaryotic community structures associated with ferromanganese nodules in the Clarion-Clipperton Zone (Pacific Ocean) revealed by 16S rRNA gene amplicon sequencing

Although deep-sea ferromanganese nodules are a potential resource for exploitation, their formation mechanisms remain unclear. Several nodule-associated prokaryotic species have been identified by amplicon sequencing of 16S rRNA genes and are assumed to contribute to nodule formation. However, the recent development of amplicon sequence variant (ASV)-level monitoring revealed that closely related prokaryotic populations within an operational taxonomic unit often exhibit distinct ecological properties. Thus, conventional species-level monitoring might have overlooked nodule-specific populations when distinct populations of the same species were present in surrounding environments. Herein, we examined the prokaryotic community diversity of nodules and surrounding environments at the Clarion-Clipperton Zone in Japanese licensed areas by 16S rRNA gene amplicon sequencing with ASV-level resolution for three cruises from 2017 to 2019. Prokaryotic community composition and diversity were distinct by habitat type: nodule, nodule-surface mud, sediment, bottom water and water column. Most ASVs (~80%) were habitat-specific. We identified 178 nodule-associated ASVs and 41 ASVs associated with nodule-surface mud via linear discriminant effect size analysis. Moreover, several ASVs, such as members of SAR324 and Woeseia, were highly specific to nodules. These nodule-specific ASVs are promising targets for future investigation of the nodule formation process

Identification of a new interaction mode between the Src homology 2 domain of C-terminal Src kinase (Csk) and Csk-binding protein/phosphoprotein associated with glycosphingolipid microdomains

This research was originally published in Journal of Biological Chemistry. Hiroaki Tanaka, Ken-ichi Akagi, Chitose Oneyama, Masakazu Tanaka, Yuichi Sasaki, Takashi Kanou, Young-Ho Lee, Daisuke Yokogawa, Marc-Werner Dobenecker, Atsushi Nakagawa, Masato Okada and Takahisa Ikegami. Identification of a new interaction mode between the Src homology 2 domain of C-terminal Src kinase (Csk) and Csk-binding protein/phosphoprotein associated with glycosphingolipid microdomains. Journal of Biological Chemistry. 2013; 288, 15240-15254. © the American Society for Biochemistry and Molecular Biology

Local magnetic structure due to inhomogeneity of interaction in S=1/2 antiferromagnetic chain

We study the magnetic properties of $S=1/2$ antiferromagnetic Heisenberg chains with inhomogeneity of interaction. Using a quantum Monte Carlo method and an exact diagonalization method, we study bond-impurity effect in the uniform $S=1/2$ chain and also in the bond-alternating chain. Here `bond impurity' means a bond with strength different from those in the bulk or a defect in the alternating order. Local magnetic structures induced by bond impurities are investigated both in the ground state and at finite temperatures, calculating the local magnetization, the local susceptibility and the local field susceptibility. We also investigate the force acting between bond impurities and find the force generally attractive.Comment: 15pages, 34figure

Measurement of Apparent Electrical Impedance of Soil with Water Flow Inside

Understanding the flow of groundwater is very important, not only for water management but also for the prevention and mitigation of natural disasters. The electrical resistivity method has been established as an effective groundwater exploration method in geological surveys. The purpose of this study is to develop an accurate investigation method for groundwater flow using soil impedance fluctuations. As a preliminary experiment, the apparent soil impedance was measured by applying a low-frequency current through a soil column with water flow inside. The apparent impedance showed fluctuations due to water flow at frequencies above 20 Hz, and the fluctuation range increased with the flow rate of water. It has been proposed that groundwater flow can be detected by measuring impedance fluctuations, and it is considered that this method can be applied to groundwater surveys and embankment and reservoir leak surveys

Microglial process dynamics depend on astrocyte and synaptic activity

Microglial processes survey the brain parenchyma, but it is unknown whether this process is influenced by the cell activity of nearby microglia under physiological conditions. Herein, we showed that microglial process dynamics differ when facilitated by astrocytic activity and pre-synaptic activity. The results revealed distinct microglial process dynamics associated with the activity of other brain cells