154 research outputs found
Ghostbusters in supergravity
supergravity is known to contain a ghost mode associated with
higher-derivative terms if it contains with greater than two.We
remove the ghost in supergravity by introducing auxiliary gauge field to
absorb the ghost. We dub this method as the ghostbuster
mechanism~\cite{Fujimori:2016udq}. We show that the mechanism removes the ghost
supermultiplet but also terms including with , after integrating
out auxiliary degrees of freedom. For pure supergravity case, there appears an
instability in the resultant scalar potential. We then show that the
instability of the scalar potential can be cured by introducing matter
couplings in such a way that the system has a stable potential.Comment: 24 pages, v2: comments, references, new section added, version
published in JHE
The meteorological condition for larger avalanches at Senjojiki Bowl in Japanese Central Alps
The Senjojiki Bowl has a typical avalanche terrain consisting of8 avalanche tracks. During the last 25 years 16 alpinists and ropeway workers in total have been killed by avalanches. Since no reliable avalanche warning is issued by the Meteorological Agency, the ropeway company and an alpine guide has collected data on avalanches in the bowl since 1987 forthe safety oftheir guests. Using the data over the last three winters, we have analyzed the meteorological conditions leading to larger avalanches descending. It was Dund that the larger avalanches occurred only under the Dllowing simple conditions: l. cold snow storm type in high-winter, 2. warmer snowy type in high-winter, 3. wet snowy type in late winter and 4. rain storm type
Non-Abelian Half-Quantum Vortices in Topological Superfluids
The existence and stability of non-Abelian half-quantum vortices (HQVs) are
established in superfluids in neutron stars with strong magnetic
fields, the largest topological quantum matter in our Universe. Using a
self-consistent microscopic framework, we find that one integer vortex is
energetically destabilized into a pair of two non-Abelian HQVs due to the
strong spin-orbit coupled gap functions. We find a topologically protected
Majorana fermion on each HQV, thereby providing two-fold non-Abelian anyons
characterized by both Majorana fermions and a non-Abelian first homotopy group.Comment: 6 pages, 4 figure
Optoelectronic parallel-matching architecture : architecture description, performance estimation, and prototype demonstration
This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/AO.40.000283 Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law
骨欠損再建における培養細胞シートを併用した培養人工骨移植の有用性
AIM: To determine the effects of transplanting osteogenic matrix cell sheets and beta-tricalcium phosphate (TCP) constructs on bone formation in bone defects.
METHODS: Osteogenic matrix cell sheets were prepared from bone marrow stromal cells (BMSCs), and a porous TCP ceramic was used as a scaffold. Three experimental groups were prepared, comprised of TCP scaffolds (1) seeded with BMSCs; (2) wrapped with osteogenic matrix cell sheets; or (3) both. Constructs were implanted into a femoral defect model in rats and bone growth was evaluated by radiography, histology, biochemistry, and mechanical testing after 8 wk.
RESULTS: In bone defects, constructs implanted with cell sheets showed callus formation with segmental or continuous bone formation at 8 wk, in contrast to TCP seeded with BMSCs, which resulted in bone non-union. Wrapping TCP constructs with osteogenic matrix cell sheets increased their osteogenic potential and resulting bone formation, compared with conventional bone tissue engineering TCP scaffolds seeded with BMSCs. The compressive stiffness (mean ± SD) values were 225.0 ± 95.7, 30.0 ± 11.5, and 26.3 ± 10.6 MPa for BMSC/TCP/Sheet constructs with continuous bone formation, BMSC/TCP/Sheet constructs with segmental bone formation, and BMSC/TCP constructs, respectively. The compressive stiffness of BMSC/TCP/Sheet constructs with continuous bone formation was significantly higher than those with segmental bone formation and BMSC/TCP constructs.
CONCLUSION: This technique is an improvement over current methods, such as TCP substitution, and is useful for hard tissue reconstruction and inducing earlier bone union in defects.博士(医学)・乙第1366号・平成27年11月27日Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved. This article is an open-access article which was
selected by an in-house editor and fully peer-reviewed by external
reviewers. It is distributed in accordance with the Creative
Commons Attribution Non Commercial (CC BY-NC 4.0) license,which permits others to distribute, remix, adapt, build upon this
work non-commercially, and license their derivative works on
different terms, provided the original work is properly cited and
the use is non-commercial. See: http://creativecommons.org/
licenses/by-nc/4.0
Rheo-optical Raman study of microscopic deformation in high-density polyethylene under hot drawing
In situ observation of the microscopic structural changes in high-density polyethylene during hot drawing was performed by incorporating a temperature-controlled tensile machine into a Raman spectroscopy apparatus. It was found that the load sharing and molecular orientation during elongation drastically changed at 50°C. The microscopic stress of the crystalline chains decreased with increasing temperature and diminished around 50°C. Moreover, the orientation of the crystalline chains was greatly promoted above 50°C. These microscopic structural changes were caused by the thermal activation of the molecular motion within lamellar crystalline chains owing to the onset of relaxation of the crystalline phase. © 2015 Elsevier Ltd. All rights reserved.Embargo Period 24 month
Discovery of the fish host of the ‘planktonic’ caligid Caligus undulatus Shen & Li, 1959 (Crustacea: Copepoda: Siphonostomatoida)
The siphonostomatoid copepod Caligus undulatus Shen & Li, 1959 has been widely reported from plankton samples obtained from neritic and oceanic waters off coasts of the Indo-West Pacific and Atlantic Oceans. Until now, its fish host has remained unknown. This copepod belongs to an intriguing group of congeners that, despite being part of a chiefly parasitic group, are consistently found as zooplankters. Quite unexpectedly, in October 2019, a fish host of C. undulatus was discovered in the Seto Inland Sea, Japan—namely, the Japanese sardinella Sardinella zunasi (Bleeker, 1854). Both juvenile (chalimus) and adult individuals of this caligid were observed as parasites of the fish host. The discovery suggests that the species has an alternative life cycle as previously proposed for other purportedly ‘planktonic’ congeners and might frequently switch hosts during the adult stage. Thus, the C. undulatus group is newly proposed as a species group in the genus, in which five species are known as planktonic. Some hypotheses on the modified life cycle of caligids also briefly discussed
Deformation mechanism of high-density polyethylene probed by in situ Raman spectroscopy
The microscopic mechanism of high-density polyethylene under uniaxial drawing is investigated using in situ Raman spectroscopy. From the peak shifts of the symmetric and anti-symmetric C-C stretching modes, it is found that the load sharing on the polymer chain in the yielding region is anisotropic with stretching along the chain and compression perpendicular to the chain. The orientation functions (〈P2〉 and 〈P4〉) as well as the orientation distribution function (N(θ)) are determined from the polarized Raman spectra. The molecular orientation with cold drawing is found to proceed more effectively for lower crystallinity specimens. In the yielding region, it is also found that N(θ) has a maximum at the polar angle θ = 30-70°. This peculiar behavior in the microscopic scale is explained by the preferential collapse of spherulites and the existence of lamellar clusters as the bulky mobile units
Investigation of molecular mechanisms of melting and crystallization of isotactic polypropylene by in situ Raman spectroscopy
金沢大学理工研究域自然システム学系In situ Raman spectroscopy has been used to reveal the molecular behavior of isotactic polypropylene during melting and crystallization. The 400 cm-1 band assigned to C-C-C bending shows a blue-shift during heating, suggesting an increase in conformational disorder, whereas the 1330 cm-1 band assigned to CH2 twisting shows a red-shift owing to an increase in the interchain distance. We suggest that interchain expansion proceeds even in the melt state, while the chain conformation becomes sufficiently disordered at the melting point. During the cooling process, the peak shifts at given temperatures are essentially the same as those during heating, except for the supercooled region where the peak shifts show obvious hystereses. By extrapolating the linear correlation between the peak shift of the 400 cm-1 band and the characteristic length along the chain axis, the critical stem size for crystallization is estimated to be ∼2.4 nm. © 2017 American Chemical Society.Embargo Period 12 month
In situ Raman spectroscopic observation of polymer chains in semi-crystalline polyethylene solids
金沢大学理工研究域フロンティア工学系In situ Raman spectroscopy is applied for polyethylene solid under various environments to elucidate the morphological and conformational changes. The trans conformation retains up to higher temperature for high-density polyethylene, reflecting higher stability of the orthorhombic crystals composed of stacked trans chains. It is suggested that the conversion of the non-crystalline trans chains to the crystalline phase is the microscopic origin of thermal history in the crystallinity, whereas the transformation between the trans and gauche conformers is practically in thermal equilibrium. Microscopic and dynamic mechanism of deformation during uniaxial stretching is investigated for the molecular orientation and the microscopic load sharing on the crystalline and amorphous chains. Lower crystallinity results in smoother and higher orientation toward the stretching direction, as well as higher load on the amorphous chains, during tensile elongation.Embargo Period 12 month
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