Suzaku Observations of the Supernova Remnant N23 in the Large Magellanic Cloud

X-ray emission from the supernova remnant N23 in the Large Magellanic Cloud (LMC) is studied using the X-ray Imaging Spectrometer (XIS) onboard Suzaku. Thanks to superior energy resolution of the XIS in the soft X-ray band, we resolved H-like and He-like Oxygen K\alpha emission lines from N23 with unprecedentedly high quality, and as a result, identified a new optically thin thermal emission component with a temperature ~0.2 keV, as well as that with a temperature of ~0.5-0.7 keV previously known. This alters the estimate of the ionization timescale net from ~10^{10-11} cm^-3s to >~10^{12} cm^{-3}s. Under the assumption that N23 is still in the Sedov phase, its age evaluated from the newly discovered low temperature component is ~8000 yr, although it is possible that N23 has already moved into the radiative phase. The abundances of the heavy elements are found to be roughly consistent with those of the LMC average, which indicates that the origin of the X-ray emission of N23 is swept-up ambient material, as expected from its ionization timescale.Comment: 7 pages, 5 figures, accepted for publication in PAS

Room temperature lasing at blue wavelengths in gallium nitride microcavities

Lasing action has been demonstrated at blue wavelengths in vertical cavity surface-emitting lasers at room temperature. The microcavity was formed by sandwiching indium gallium nitride multiple quantum wells between nitride-based and oxide-based quarter-wave reflectors. Lasing action was observed at a wavelength of 399 nanometers under optical excitation and confirmed by a narrowing of the linewidth in the emission spectra from 0.8 nanometer below threshold to less than 0.1 nanometer (resolution limit) above threshold. The result suggests that practical blue vertical cavity surface-emitting lasers can be realized in gallium-nitride–based material systems

Accounting revolutions in Japan

Japan\u27s rise from a feudalistic economy to a position as a leading industrial power is a result, in part, of two revolutionary changes in its accounting structure. The first change came during the latter part of the nineteenth century as part of the Meiji Government\u27s program of modernization. Various political, economic, and cultural institutions were adopted from the West, among them the double-entry method of bookkeeping; this method gradually replaced very unsatisfactory traditional methods. The second change came after World War II, when the Allied Command set as its objective the destruction of the Zaibatsu-dominated industrial structure and its replacement with a democratic economy, in which industrial capital is accumulated through the participation of investors in a free stock exchange. Such a change demanded a shift in emphasis from stewardship-oriented financial reporting to investor-oriented financial reporting

The creature of asexual love in 'My Name is Shingo'

This article discusses the story of Kazuo Umezu’s book, Watashi wa Shingo (My name is Shingo) (1982-1986) within the context of asexuality. Readers see how two elementary school pupils, a girl named Marine and a boy named Satoru, fall in love and are blessed with a rather unorthodox child which happens to be a robot. This robot is called Shingo and the story recounts how its mind develops and how it travels the world in pursuit of its ‘parents’ whom it has never had the chance to meet. The reason why I would like to discuss the comic book, My Name is Shingo, is because it hints at children’s asexual reproduction, as well as child asexuality, which, I think, contributes significantly to the intensity and uniqueness of the story. In this article I would like to consider the meaning of ‘asexuality’ and whether there exists any similarities between asexuality of children and that of adults.AsiaPacifiQueer Network, Australian National Universit

Rapid increase in strength of vortices and a directional net flow due to Marangoni force in Büttiker–Landauer ratchet

The control of the vortex flow is interesting because it may open a new way to use low-grade energy. In this study, we report a rapid increase in the strength of vortices and a directional net flow at the classical threshold Rayleigh number in the Büttiker–Landauer (BL) ratchet. In particular, by increasing the temperature difference of the BL ratchet made by connecting plural liquid chambers with flow channels that generate Marangoni force, we succeed in observing this transition. Furthermore, we show that our simple transition model that considers a critical Rayleigh number explains the experimental results qualitatively. In addition, as a result, we succeed in producing a net flow without using the additional guide-walls that prevent the isolation of the vortex flows among the plural liquid chambers.Physics of Fluids 34, 064113 (2022)journal articl

Printed skin-like large-area flexible sensors and actuators

AbstractIn ambient electronics in the next generation, multiple electronic objects are scattered on walls, ceilings or in imaginative locations and interact each other to enhance safety, security and convenience. For implementation of many electronic objects in our daily life, large-area sheet-type flexible devices are expected to play an important role. In this paper, we review recent progress and future prospects of printed skin-like large-area flexible sensors and actuators. Moreover, the issues and the future prospect of flexible devices such as printed plastic MEMS devices and organic transistors will be addressed from the view point of ambient electronics

Complete Nucleotide Sequence of the Chiba Virus Genome and Functional Expression of the 3C-Like Protease in Escherichia coli

AbstractWe cloned the genome RNA of the Chiba virus (ChV; Hu/NLV/Chiba 407/1987/JP) and determined its complete nucleotide sequence. The genome is predicted to be a positive-sense, single-stranded RNA of 7697 bases, excluding a poly(A) tract. Comparison of the nucleotide and amino acid sequences with those of other members of the species Norwalk virus (NV) revealed that ChV belongs to genogroup I NV. The ChV genome contains three open reading frames (ORFs). A large 5′-terminal ORF (ORF1) encodes a polyprotein with 1785 amino acids that are likely processed into functional proteins, including RNA helicase, VPg, protease, and RNA-dependent RNA polymerase. ORF2 encodes the capsid protein with 544 amino acids, and a small 3′-terminal ORF (ORF3) encodes a basic protein with 208 amino acids. The amino acid sequences of five cleavage sites in ORF1 are highly conserved compared with those of other members of NV. When expressed in Escherichia coli, the glutathione-S-transferase (GST) fusion protein of the ChV protease connected via a short peptide containing a human rhinovirus 3C protease cleavage site was cleaved into GST and the protease; however, this cleavage did not occur when the Cys mutation was introduced into the putative active site of the protease. Moreover, the ChV protease recognized and cleaved the predicted proteolytic sites between VPg and protease and between protease and RNA polymerase. Therefore, the ChV protease expressed in E. coli retained an enzymatic activity and a substrate specificity similar to that of the human rhinovirus 3C protease

Silver-catalyzed coupling reactions of alkyl halides with indenyllithiums

Coupling reactions of tertiary and secondary alkyl halides with indenyllithiums proceeded effectively in the presence of a catalytic amount of silver bromide to provide tertiary- and secondary-alkyl-substituted indene derivatives in good yields