Curved Superspaces and Local Supersymmetry in Supermatrix Model

In a previous paper, we introduced a new interpretation of matrix models, in which any d-dimensional curved space can be realized in terms of d matrices, and the diffeomorphism and the local Lorentz symmetries are included in the ordinary unitary symmetry of the matrix model. Furthermore, we showed that the Einstein equation is naturally obtained, if we employ the standard form of the action, S=-tr([A_a,A_b][A^a,A^b])+.... In this paper, we extend this formalism to include supergravity. We show that the supercovariant derivatives on any d-dimensional curved space can be expressed in terms of d supermatrices, and the local supersymmetry can be regarded as a part of the superunitary symmetry. We further show that the Einstein and Rarita-Schwinger equations are compatible with the supermatrix generalization of the standard action.Comment: 23 pages, 1 figure, PTPTeX. Eqs. (2.18), (2.19) and related comments modifie

Describing Curved Spaces by Matrices

It is shown that a covariant derivative on any d-dimensional manifold M can be mapped to a set of d operators acting on the space of functions on the principal Spin(d)-bundle over M. In other words, any d-dimensional manifold can be described in terms of d operators acting on an infinite dimensional space. Therefore it is natural to introduce a new interpretation of matrix models in which matrices represent such operators. In this interpretation the diffeomorphism, local Lorentz symmetry and their higher-spin analogues are included in the unitary symmetry of the matrix model. Furthermore the Einstein equation is obtained from the equation of motion, if we take the standard form of the action S=-tr([A_{a},A_{b}][A^{a},A^{b}]).Comment: 22 pages, 1 figure. V3: eqs (80) and (81) correcte

Conferring the ability to utilize inorganic polyphosphate on ATP-specific NAD kinase

ATP特異性の獲得メカニズムの解明 : 新薬と新しい物質生産系の開発に期待. 京都大学プレスリリース. 2013-09-11.NAD kinase (NADK) is a crucial enzyme for production of NADP(+). ATP-specific NADK prefers ATP to inorganic polyphosphate [poly(P)] as a phosphoryl donor, whereas poly(P)/ATP-NADK utilizes both ATP and poly(P), and is employed in industrial mass production of NADP(+). Poly(P)/ATP-NADKs are distributed throughout Gram-positive bacteria and Archaea, whereas ATP-specific NADKs are found in Gram-negative α- and γ-proteobacteria and eukaryotes. In this study, we succeeded in conferring the ability to utilize poly(P) on γ-proteobacterial ATP-specific NADKs through a single amino-acid substitution; the substituted amino-acid residue is therefore important in determining the phosphoryl-donor specificity of γ-proteobacterial NADKs. We also demonstrate that a poly(P)/ATP-NADK created through this method is suitable for the poly(P)-dependent mass production of NADP(+). Moreover, based on our results, we provide insight into the evolution of bacterial NADKs, in particular, how NADKs evolved from poly(P)/ATP-NADKs into ATP-specific NADKs

Two Cases of Duodenal Ulcers That Developed after Transcatheter Procedures for Unruptured Visceral Artery Aneurysms

Herein, we report two cases of duodenal ulcers that developed after transcatheter procedures for the treatment of unruptured artery aneurysms. Both patients recovered after the administration of nothing by mouth, intravenous fluids, and proton-pump inhibitors. Notably, the duodenal ulcer was unchanged in one patient six days after endovascular treatment and improved in the other patient 13 days after angiography. These cases suggest that conservative treatment is acceptable in patients with duodenal ischemia that develops as an adverse effect of endovascular procedures. The usefulness of esophagogastroduodenoscopy in such patients has also been highlighted

Magnetic properties of epitaxial Fe3_3O4_4 films with various crystal orientations and TMR effect in room temperature

Fe$_3$O$_4$ is a ferrimagnetic spinel ferrite that exhibits electric conductivity at room temperature (RT). Although the material has been predicted to be a half metal according to ab-initio calculations, magnetic tunnel junctions (MTJs) with Fe$_3$O$_4$ electrodes have demonstrated a small tunnel magnetoresistance effect. Not even the sign of the TMR ratio has been experimentally established. Here, we report on the magnetic properties of epitaxial Fe$_3$O$_4$ films with various crystal orientations. The films exhibited apparent crystal orientation dependence on hysteresis curves. In particular, Fe$_3$O$_4$(110) films exhibited in-plane uniaxial magnetic anisotropy. With respect to the squareness of hysteresis, Fe$_3$O$_4$ (111) demonstrated the largest squareness. Furthermore, we fabricated MTJs with Fe$_3$O$_4$(110) electrodes, and obtained an TMR effect of -12\% at RT. The negative TMR ratio corresponded to the negative spin polarization of Fe$_3$O$_4$ predicted from band calculations

Detecting Train Delays using Railway Network Topology in Twitter

This paper presents a novel train delay detection method based on topic propagation analysis of geo-tagged tweets between railway stations. Our goal is to detect traffic accidents and to predict train delays in railway network topology by tracing how relevant tweets propagate in real space and cyberspace. In our method, we utilize railway network as the topology of real space, and extract the topology of social network that is mapped on the railway network. This permits observing the influence of delays on stations with a few tweets, or predicting related tweets of affected stations even if the tweets contain indirect topics about delays