Tohoku University

About: Tohoku University is a education organization based out in Sendai, Japan. It is known for research contribution in the topics: Magnetization & Alloy. The organization has 72116 authors who have published 170791 publications receiving 3941714 citations. The organization is also known as: Tōhoku daigaku.

The OsHMA2 transporter is involved in root‐to‐shoot translocation of Zn and Cd in rice

Abstract: Zinc (Zn) is an essential micronutrient for plants and humans. Cadmium (Cd) is a Zn analog and one of the most toxic heavy metals to humans. Here we investigated the role of the Zn/Cd transporter OsHMA2. OsHMA2:GFP fusion protein localized to the plasma membrane in onion epidermal cells. The yeast expressing OsHMA2 was able to reverse the growth defect in the presence of excess Zn. The expression of OsHMA2 in rice was observed mainly in the roots where OsHMA2 transcripts were abundant in vascular bundles. Furthermore, Zn and Cd concentrations of OsHMA2-suppressed rice decreased in the leaves, while the Zn concentration increased in the roots compared with the wild type (WT). These results suggest that OsHMA2 plays a role in Zn and Cd loading to the xylem and participates in root-to-shoot translocation of these metals in rice. Furthermore, the Cd concentration in the grains of OsHMA2-overexpressing rice as well as in OsSUT1-promoter OsHMA2 rice decreased to about half that of the WT, although the other metal concentrations were the same as in the WT. A phenotype that reduces only the Cd concentration in rice grains will be very useful for transgenic approaches to food safety.

Microlensing constraints on primordial black holes with Subaru/HSC Andromeda observations

Abstract: Primordial black holes (PBHs) have long been suggested as a viable candidate for the elusive dark matter. The abundance of such PBHs has been constrained using a number of astrophysical observations, except for a hitherto unexplored mass window of MPBH = [10−14, 10−9] solar masses. Here we carry out a dense-cadence, 7-hour-long observation of M31 with the Subaru Hyper Suprime-Cam (HSC) to search for microlensing of stars in M31 by PBHs lying in the halo regions of the Milky Way and M31. Given our simultaneous monitoring of tens of millions of stars in M31, if such light PBHs make up a significant fraction of dark matter, we expect to find many microlensing events. However, we identify only a single candidate event, which translates into stringent upper bounds on the abundance of PBHs in the mass range MPBH ≃ [10−11, 10−6] solar masses. The abundance of primordial black holes in the Galactic halo is constrained through their microlensing of stars in M31. Despite monitoring tens of millions of stars, only a single candidate event is found, providing stringent upper bounds on their abundance.

Limit on neutrinoless ββ decay of Xe136 from the first phase of KamLAND-Zen and comparison with the positive claim in Ge76

Abstract: We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of Xe136. We obtain a lower limit for the neutrinoless double-beta decay half-life of T0ν1/2>1.9×1025 yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T0ν1/2>3.4×1025 yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of ⟨mββ⟩<(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in Ge76, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.