Why has Japan shifted towards a more active security posture since the end of the Cold War? Japan's security policy under Prime Minister Abe has triggered numerous discussions on the changing nature ...of Japan as a security actor. This article identifies two independent variables-the balance of power calculations and secure access to the maritime commons-that informs Japan's security policy trajectory. It argues that Japanese strategy is best described as 'maritime realism', a posture in which liberal internationalist and realist elements draw upon principles of maritime strategy to fuse together. Japan has not only actively facilitated US commitment to maritime Asia but also focused on expanding its role in maritime security as the maritime space in the Indo-Pacific has increasingly become a contested space. While Tokyo's security policy corresponds with structural realist predictions, they have also been frequently expressed in liberal internationalist language given the peculiar nature of the role of navies. This article's findings advance theoretical debates on alliance politics and great power competition by integrating international relations and concepts in strategic studies. It also contains significant explanatory power in assessing the trajectory of Japan's defence policy since the end of the Cold War.
How to create a superintelligence Matsuda, Takuya
Cognitive Studies: Bulletin of the Japanese Cognitive Science Society,
2022/03/01, Letnik:
29, Številka:
1
Journal Article
Odprti dostop
We discuss possible paths to create a superintelligence, which is an artificial general intelligence (AGI) of immense intellectual capacity. We argue that the creation of the superintelligence has ...huge political/economic/cultural impacts on the world. There could be two approaches to creating AGI: the biological approach and the engineering one. In the former case, it is necessary to find the master algorithm operating in the human neocortex. We argue that a possible model of the master algorithm is a dynamical Bayesian network. In the latter approach, we are witnessing a big progress in Natural Language Processing AI such as Transformer, BERT, GPT-3 etc. which are exhibiting a glimpse of real human intelligence. We discuss that the key element is the attention mechanism.
Abstract
Antiferromagnetic spin motion at terahertz (THz) frequencies attracts growing interests for fast spintronics, however, their smaller responses to external field inhibit device application. ...Recently the noncollinear antiferromagnet Mn
3
Sn, a Weyl semimetal candidate, was reported to show large anomalous Hall effect (AHE) at room temperature comparable to ferromagnets. Dynamical aspect of such large responses is an important issue to be clarified for future THz data processing. Here the THz anomalous Hall conductivity in Mn
3
Sn thin films is investigated by polarization-resolved spectroscopy. Large anomalous Hall conductivity
$${\mathrm{Re}}\;\sigma _{xy}\left( \omega \right) \sim 20\;{\mathrm{\Omega }}^{ - 1}{\mathrm{cm}}^{ - 1}$$
Re
σ
x
y
ω
~
20
Ω
−
1
cm
−
1
at THz frequencies is clearly observed as polarization rotation. A peculiar temperature dependence corresponding to the breaking/recovery of symmetry in the spin texture is also discussed. Observation of the THz AHE at room temperature demonstrates the ultrafast readout for the antiferromagnetic spintronics using Mn
3
Sn, and will also open new avenue for studying nonequilibrium dynamics in Weyl antiferromagnets.
The rph gene cluster for prodigiosin biosynthesis has been identified in Streptomyces griseoviridis 2464-S5, which produces cyclic prodigiosin derivatives including roseophilin (2), prodigiosin R1 ...(3) and prodigiosin R2 (4). A new cyclic prodigiosin, prodigiosin R3 (1), was produced by the redG redP double disruptant of Streptomyces coelicolor M511 expressing four cyclization gene candidates (rphG, rphG2, rphG3 and rphG4) in the rph cluster. The same compound was isolated from Streptomyces griseoviridis 2464-S5. The molecular formula of 1 was established as C
H
N
O by ESI and FAB mass spectrometry. The structure was determined to be a multicyclic prodigiosin with three alkyl linkages by NMR spectroscopic analysis. Prodigiosin R3 (1) showed cytotoxicity against HeLa human cervical carcinoma cells and HT1080 human fibrosarcoma cells with IC
s of 2.1 µM and 3.2 µM, respectively.
Pentatricopeptide repeat (PPR) proteins, composed of PPR motifs repeated in tandem, are sequence-specific RNA binding proteins. Recent bioinformatic studies have shown that the combination of polar ...amino acids at positions 5 and last in each PPR motif recognizes RNA bases, and an RNA recognition code for PPR proteins has been proposed. Subsequent studies confirmed that the P (canonical length) and S (short) motifs bind to specific nucleotides according to this code. However, the contribution of L (long) motifs to RNA recognition is mostly controversial, owing to the presence of a nonpolar amino acid at position 5. The PLS-class PPR protein PpPPR_56 is a mitochondrial RNA editing factor in the moss Physcomitrella patens. Here, we performed in vitro RNA binding and in vivo complementation assays with PpPPR_56 and its variants containing mutated L motifs to investigate their contributions to RNA recognition. In vitro RNA binding assay showed that the original combination of amino acids at positions 5 and last in the L motifs of PpPPR_56 is not required for RNA recognition. In addition, an in vivo complementation assay with RNA editing factors PpPPR_56 and PpPPR_78 revealed the importance of nonpolar amino acids at position 5 of C-terminal L motifs for efficient RNA editing. Our findings suggest that L motifs function as non-binding spacers, not as RNA-binding motifs, to facilitate the formation of a complex between PLS-class PPR protein and RNA. As a result, the DYW domain, a putative catalytic deaminase responsible for C-to-U RNA editing, is correctly placed in proximity to C, which is to be edited.
Myocardial ischemia is caused by a mismatch between myocardial oxygen consumption and oxygen delivery in coronary artery disease (CAD). Stratification and decision-making based on ischemia improves ...the prognosis in patients with CAD. Non-invasive tests used to evaluate myocardial ischemia include stress electrocardiography, echocardiography, single-photon emission computed tomography, and magnetic resonance imaging. Invasive fractional flow reserve is considered the reference standard for assessment of the hemodynamic significance of CAD. Computed tomography (CT) angiography has emerged as a first-line imaging modality for evaluation of CAD, particularly in the population at low to intermediate risk, because of its high negative predictive value; however, CT angiography does not provide information on the hemodynamic significance of stenosis, which lowers its specificity. Emerging techniques, e.g., CT perfusion and CT-fractional flow reserve, help to address this limitation of CT, by determining the hemodynamic significance of coronary artery stenosis. CT perfusion involves acquisition during the first pass of contrast medium through the myocardium following pharmacological stress. CT-fractional flow reserve uses computational fluid dynamics to model coronary flow, pressure, and resistance. In this article, we review these two functional CT techniques in the evaluation of myocardial ischemia, including their principles, technology, advantages, limitations, pitfalls, and the current evidence.
The electromagnetic response of Dirac semimetals in the infrared and terahertz frequency ranges is attracting growing interest for potential applications in optoelectronics and nonlinear optics. The ...interplay between the free-carrier response and interband transitions in the gapless, linear dispersion relation plays a key role in enabling novel functionalities. Here we investigate ultrafast dynamics in thin films of a photoexcited Dirac semimetal Cd3As2 by probing the broadband response functions as complex quantities in the multiterahertz region (10–45 THz, 40–180 meV, or 7–30 μm), which covers the crossover between the inter- and intraband response. We resolve dynamics of the photoexcited nonthermal electrons, which merge with originally existing carriers to form a single thermalized electron gas and how it is facilitated by high-density excitation. We also demonstrate that a large reduction of the refractive index by 80% dominates the nonequilibrium infrared response, which can be utilized for designing ultrafast switches in active optoelectronics.
The coherent volume of single quantum states of matter is typically smaller than that of photons by several orders of magnitude, and hence, interactions between photons and single quantum states are ...normally very weak. This limits the speed of radiative decay of matter states in free space. Recent efforts to speed-up radiative processes have been focused on creating a small mode volume of photons using cavity systems, or on realizing spontaneous synchronization among quantum emitters to create a dipole at the macroscopic scale, which accelerates photon emission up to a couple of hundred femtoseconds. Here, we demonstrate the 10-fs class of photoluminescence (PL) of a single quantum state in solid thin films without the use of a photo-cavity system or the spontaneous synchronization effect. Significantly, this speed can beat thermal dephasing of relevant excited states at room temperature, which is typically a couple of tens of femtoseconds. The process occurs due to the giant interaction volume between light waves and the multipole excitonic waves. This result indicates the possibility to realize photoemission processes that complete before the thermal dephasing process activates, which opens up the hidden potential of ubiquitous solids as thermal-free or extremely low-energy-loss photonic materials.
The prevalence of overweight and obesity has increased, not just in adults but also in children. In Japan, the percentage of overweight (POW) is widely used for the estimation and assessment of ...percentage body fat (PBF) for children. We examine whether there is a difference between normal height and short stature children in terms of the relationship between POW and PBF.
A total of 321 children of normal height (163 boys, 158 girls) and 106 children with short stature (78 boys, 28 girls) were assessed according to sex. Percentage of overweight was used to represent the degree of obesity. The PBF of the total body was examined by dual energy X-ray absorptiometry.
According to their PBF, normal height subjects of both sexes were classified as obese if they had a POW of more than 20%. However, short-stature subjects of both sexes were not classified as obese until the boys had a POW of 40%, and girls had a POW of 35%, respectively. Thus, overweight or obesity is overestimated in short stature children in both males and females with the rule "POW above 20% is recognized as obesity."
Percentage of overweight is commonly considered as a good surrogate measure for determining overweight and obesity in children of both sexes. However, this study has clarified that body fat accumulation is overestimated in children with short stature when using the POW measurement.
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