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The analysis of bulk and boundary causalities in asymptotically Anti-de Sitter spacetime
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Normally-off AlGaN/GaN MIS-HEMTs with high 2DEG mobility enabled by shallow recess and oxygen plasma treatment
No full textWe demonstrate a normally-off operation in Al2O3/AlGaN/GaN MIS-HEMTs with a high two-dimensional electron gas (2DEG) mobility enabled by a shallow recess channel structure and oxygen plasma treatment. In the channel region, the original 25-nm-thick AlGaN barrier layer was thinned down to 9 nm, which in principle, should yield a normally-on operation. However, we show that a pre-insulator deposition oxygen plasma treatment shifts the threshold voltage to +1.4 V. The relatively thick AlGaN barrier facilitated a minimal sacrifice of channel 2DEG mobility retaining a value as high as 1800 cm2V^−1s^−1, resulting in a high drain current of 600 mA mm^−1.journal articl
Tuning the clock with BMAL1 ligand
No full textThe identification of a small molecule selectively targeting the core circadian clock protein BMAL1 provides deeper insights into the molecular mechanisms governing biological rhythms and enables control of immune pathways.journal articl
Blurring Self-touch Improves Sense of Body Ownership in Incongruence Between VR Avatar and Real User’s Body Part
No full textAs an application of Virtual Reality (VR) technology, VR programs have been proposed to simulate on-site experiences, such as practical training, in a virtual environment. To make users feel as if they are actually experiencing these activities in the virtual environment, it is important to design the program to increase the sense of body ownership and presence. However, in practical applications of such VR programs, little is known about the negative effects of using consumer-grade VR devices with limited tracking capabilities on body ownership and presence, and about methods to mitigate these effects. Limitations in tracking capabilities can cause discrepancies in the positional alignment of body parts between the user and their avatar, leading to incongruence between visual information and tactile feedback when users touch their own bodies. Developing methods to mitigate the effects of such inconsistent self-touch is essential for making VR programs accessible at the consumer level. The purpose of this study is to investigate the negative effects of incongruent self-touch on the sense of body ownership and presence and to develop a novel method to mitigate these effects by using visual effects to blur the areas where self-touch occurs. The results of the preliminary experiment suggest that VR devices with low tracking capabilities negatively effect the quality of the VR program experience, and the proposed method utilizing visual effects to mitigate this impact has shown potential effectiveness.Chen, J.Y.C., Fragomeni, G. (eds) Virtual, Augmented and Mixed Reality. HCII 2025. Lecture Notes in Computer Science, vol 15790. Springer, Cham.book par
Geometrical impedance matching for weak shock waves at shock tube end wall
No full textWhen a shock wave encounters an interface with a medium of different acoustic impedance, a reflected wave is generated. It is a shock wave if the medium has a higher acoustic impedance or an expansion fan if the impedance is lower. When the acoustic impedances are perfectly matched, no wave is reflected—a phenomenon known as “impedance matching.” This study aims to achieve a similar effect by varying the geometry of the shock tube exit. Assuming a steady-state, quasi-one-dimensional and subsonic post flow, we derived the exit geometry condition under which neither shock waves nor expansion waves are reflected. To validate this condition, we conducted shock tube experiments with shock Mach numbers up to approximately 1.07, and found that the shock wave reflection behavior is influenced not only by the cross-sectional area ratio of the tube but also by the specific shape of the orifice. In tests with a simple converging orifice shape, a pressure spike occurred due to the leading reflected shock wave before the pressure stabilized. The overpressure of this spike was reduced to 7 × 10^-3 times the pressure ahead of the spike by installing perforated sections and a porous metal body on the sidewall just upstream of the orifice. This study offers a new approach to suppress post-shock pressure fluctuations in practical applications such as high-speed trains entering tunnels and within exhaust pipes of internal combustion engines, as well as to extend the test duration of shock tube experiments.journal articl
Paddy-upland rotation makes distinct impacts on the abundance of methane-oxidizing and ammonia-oxidizing microbial communities in paddy field soil
No full textPaddy-upland rotation systems have been used as a major land management of paddy fields in Japan. In the paddy-upland rotational fields, upland crops are cultivated under drained conditions in summer for one year to several years, followed by paddy rice cropping for one year to several years. The soil conditions are kept oxic during the upland periods in these fields. Microbial communities in paddy field soil are greatly affected by these managements. In the present study, effect of paddy-upland rotation on the abundance of methane-oxidizing bacteria (MOB) and ammonia-oxidizing bacteria (AOB) and archaea (AOA) was investigated. Soil samples were collected from the rotational plots and consecutive paddy (control) plots at the experimental fields, where paddy rice under flooded conditions was rotated with soybean under upland conditions at different rotation histories. Abundance of MOB, AOB, and AOA communities was estimated by the quantitative PCR analyses of pmoA and amoA genes for DNAs extracted from the soil samples. The gene abundance of pmoA of MOB was an order of magnitude greater in the consecutive paddy plots (10^6 copies g^−1 dry soil) than in the rotational plots (10^5 copies g^−1 dry soil). In contrast, the gene abundance of amoA of AOB was an order of magnitude greater in the rotational plots (10^8 copies g^−1 dry soil) than in the consecutive paddy plots (10^7 copies g^−1 dry soil). The gene abundance of amoA of AOA was on the order of 10^9 copies g^−1 dry soil both in the rotational and consecutive paddy plots and showed very small differences between the plots. These results indicated that the factors affecting fluctuation in the community abundance caused by the paddy-upland rotation could be different among MOB, AOB, and AOA in the paddy field soil.Published online: 13 Jun 2025journal articl