139 research outputs found
Higher Order Terms of Improved Mean Field Approximation for IIB Matrix Model and Emergence of Four-dimensional Space-time
The spontaneous breakdown of SO(10) symmetry of the IIB matrix model has been
studied by using the improved mean field approximation (IMFA). In this report,
the eighth-order contribution to the improved perturbative series is obtained,
which involves evaluation of 20410 planar two-particle irreducible vacuum
diagrams. We consider SO(d)-preserving configurations as ansatz (d=4,7). The
development of plateau, the solution of self-consistency condition, is seen in
both ansatz. The large ratio of the space-time extent of d-dimensional part
against the remaining (10-d)-dimensional part is obtained for SO(4) ansatz
evaluated at the representative points of the plateau. It would be interpreted
as the emergence of four-dimensional space-time in the IIB matrix model.Comment: 13 page
Phenotypic plasticity in the mandibular morphology of Japanese macaques: captive–wild comparison
Despite the accumulating evidence suggesting the importance of phenotypic plasticity in diversification and adaptation, little is known about plastic variation in primate skulls. The present study evaluated the plastic variation of the mandible in Japanese macaques by comparing wild and captive specimens. The results showed that captive individuals are square-jawed with relatively longer tooth rows than wild individuals. We also found that this shape change resembles the sexual dimorphism, indicating that the mandibles of captive individuals are to some extent masculinized. By contrast, the mandible morphology was not clearly explained by ecogeographical factors. These findings suggest the possibility that perturbations in the social environment in captivity and resulting changes of androgenic hormones may have influenced the development of mandible shape. As the high plasticity of social properties is well known in wild primates, social environment may cause the inter- and intra-population diversity of skull morphology, even in the wild. The captive–wild morphological difference detected in this study, however, can also be possibly formed by other untested sources of variation (e.g. inter-population genetic variation), and therefore this hypothesis should be validated further
Spinal Deformity and the Musculoskeletal Cohort Study of the General Older Population
Article信州医学雑誌 69(3) : 111-120(2021)departmental bulletin pape
Dijkgraaf-Vafa theory as large-N reduction
We construct a large-N twisted reduced model of the four-dimensional super
Yang-Mills theory coupled to one adjoint matter. We first consider a
non-commutative version of the four-dimensional superspace, and then give the
mapping rule between matrices and functions on this space explicitly. The
supersymmetry is realized as a part of the internal gauge symmetry
in this reduced model. Our reduced model can be compared with the
Dijkgraaf-Vafa theory that claims the low-energy glueball superpotential of the
original gauge theory is governed by a simple one-matrix model. We show that
their claim can be regarded as the large-N reduction in the sense that the
one-matrix model they proposed can be identified with our reduced model. The
map between matrices and functions enables us to make direct identities between
the free energies and correlators of the gauge theory and the matrix model. As
a by-product, we can give a natural explanation for the unconventional
treatment of the one-matrix model in the Dijkgraaf-Vafa theory where
eigenvalues lie around the top of the potential.Comment: 34 pages, LaTeX, to appear in Nucl. Phys.
Effectiveness of long-term combined aerobic and resistance training circuits on physical function, medical examination, and cost of medical care among middle-aged women
Object Transportation System Mimicking the Cilia of Paramecium aurelia Making Use of the Light-Controllable Crystal Bending Behavior of a Photochromic Diarylethene
The design of an object transportation system exploiting the bending behavior of surface-assembled diarylethene crystals is reported. A photoactuated smart surface based on this system can transport polystyrene beads to a desired area depending on the direction of the incident light. Two main challenges were addressed to accomplish directional motion along a surface: first, the preparation of crystals whose bending behavior depends on the direction of incident light; second, the preparation of a film on which these photochromic crystal plates are aligned. Nuclei generation and nuclear growth engineering were achieved by using a roughness-controlled dotted microstructured substrate. This system demonstrates how to achieve a mechanical function as shown by remote-controlled motion along a surface
String Scale in Noncommutative Yang-Mills
We identify the effective string scale of noncommutative Yang-Mills theory
(NCYM) with the noncommutativity scale through its dual supergravity
description. We argue that Newton's force law may be obtained with 4
dimensional NCYM with maximal SUSY. It provides a nonperturbative
compactification mechanism of IIB matrix model. We can associate NCYM with the
von Neumann lattice by the bi-local representation. We argue that it is
superstring theory on the von Neumann lattice. We show that our identification
of its effective string scale is consistent with exact T-duality (Morita
equivalence) of NCYM.Comment: 28 pages, 4 figures, published version in NP
Six-month treatment with atypical antipsychotic drugs decreased frontal-lobe levels of glutamate plus glutamine in early-stage first-episode schizophrenia
The noble gas and nitrogen relationship between Ryugu and carbonaceous chondrites
Carbonaceous chondrites are considered to have originated from C-type asteroids and represent some of the most primitive material in our solar system. Furthermore, since carbonaceous chondrites can contain significant quantities of volatile elements, they may have played a crucial role in supplying volatiles and organic material to Earth and other inner solar system bodies. However, a major challenge of unravelling the volatile composition of chondritic meteorites is distinguishing between which features were inherited from the parent body, and what may be a secondary feature attributable to terrestrial weathering. In December 2020, the Hayabusa2 mission of the Japan Aerospace Exploration Agency (JAXA) successfully returned surface material from the C-type asteroid (162173) Ryugu to Earth. This material has now been classified as closely resembling CI-type chondrites, which are the most chemically pristine meteorites. The analysis of material from the surface of Ryugu therefore provides a unique opportunity to analyse the volatile composition of material that originated from a CI-type asteroid without the complications arising from terrestrial contamination. Given their highly volatile nature, the noble gas and nitrogen inventories of chondrites are highly sensitive to different alteration processes on the asteroid parent body, and to terrestrial contamination. Here, we investigate the nitrogen and noble gas signature of two pelletized grains collected from the first and second touchdown sites (Okazaki et al., 2022a), to provide an insight into the formation and alteration history of Ryugu. The concentration of trapped noble gas in the Ryugu samples is greater than the average composition of previously measured CI chondrites and are primarily derived from phase Q, although a significant contribution of presolar nanodiamond Xe-HL is noted. The large noble gas concentrations coupled with a significant contribution of presolar nanodiamonds suggests that the Ryugu samples may represent some of the most primitive unprocessed material from the early solar system. In contrast to the noble gases, the abundance of nitrogen and δ15N composition of the two Ryugu pellets are lower than the average CI chondrite value. We attribute the lower nitrogen abundances and δ15N measured in this study to the preferential loss of a 15N-rich phase from our samples during aqueous alteration on the parent planetesimal. The analyses of other grains returned from Ryugu have shown large variations in nitrogen concentrations and δ15N indicating that alteration fluids heterogeneously interacted with material now present on the surface of Ryugu. Finally, the ratio of trapped noble gases to nitrogen is higher than CI chondrites, and is closer to refractory phase Q and nanodiamonds. This indicates that Ryugu experienced aqueous alteration that led to the significant and variable loss of nitrogen, likely from soluble organic matter, without modification of the noble gas budget, which is primarily hosted in insoluble organic matter and presolar diamonds and is therefore more resistant to aqueous alteration.ISSN:0016-7037ISSN:1872-953
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