62 research outputs found
Wheeler-DeWitt Equation in AdS/CFT Correspondence
We discuss a quantum extension of the holographic RG flow equation obtained
previously from the classical Hamiltonian constraint in the bulk AdS
supergravity. The Wheeler-DeWitt equation is proposed to generate the extended
RG flow and to produce 1/N subleading corrections systematically. Our
formulation in five dimensions is applied to the derivation of the Weyl anomaly
of boundary N=4 SU(N) super-Yang-Mills theory beyond the large N limit. It is
shown that subleading 1/N^2 corrections arising from fields in AdS_5
supergravity agree with those obtained recently by Mansfield et al. using their
Schroedinger equation, thereby guaranteeing to reproduce the exact form of the
boundary Weyl anomaly after summing up all of the KK modes.Comment: 7 pages, LaTex, references adde
Quantum Back Reaction to asymptotically AdS Black Holes
We analyze the effects of the back reaction due to a conformal field theory
(CFT) on a black hole spacetime with negative cosmological constant. We study
the geometry numerically obtained by taking into account the energy momentum
tensor of CFT approximated by a radiation fluid. We find a sequence of
configurations without a horizon in thermal equilibrium (CFT stars), followed
by a sequence of configurations with a horizon. We discuss the thermodynamic
properties of the system and how back reaction effects alter the space-time
structure. We also provide an interpretation of the above sequence of solutions
in terms of the AdS/CFT correspondence. The dual five-dimensional description
is given by the Karch-Randall model, in which a sequence of five-dimensional
floating black holes followed by a sequence of brane localized black holes
correspond to the above solutions.Comment: 13 pages, 10 figure
Bulk scalar field in the braneworld can mimic the 4D inflaton dynamics
Based on the recently proposed scenario of inflation driven by a bulk scalar
field in the braneworld of the Randall-Sundrum (RS) type, we investigate the
dynamics of a bulk scalar field on the inflating braneworld. We derive the late
time behavior of the bulk scalar field by analyzing the property of the
retarded Green function. We find that the late time behavior is basically
dominated by a single (or a pair of) pole(s) in the Green function irrespective
of the initial condition and of the signature of , where
is the potential of the bulk scalar field. Including the lowest order
back-reaction to the geometry, this late time behavior can be well approximated
by an effective 4-dimensional scalar field with . The
mapping to the 4-dimensional effective theory is given by a simple scaling of
the potential with a redefinition of the field. Our result supports the picture
that the scenario of inflation driven by a bulk scalar field works in a quite
similar way to that in the standard 4-dimensional cosmology.Comment: 12 pages, no figures, final version to be published in PR
Massless scalar fields and infrared divergences in the inflationary brane world
We study the quantum effects induced by bulk scalar fields in a model with a
de Sitter (dS) brane in a flat bulk (the Vilenkin-Ipser-Sikivie model) in more
than four dimensions. In ordinary dS space, it is well known that the stress
tensor in the dS invariant vacuum for an effectively massless scalar
(m_\eff^2=m^2+\xi {\cal R}=0 with the Ricci scalar) is infrared
divergent except for the minimally coupled case. The usual procedure to tame
this divergence is to replace the dS invariant vacuum by the Allen Follaci (AF)
vacuum. The resulting stress tensor breaks dS symmetry but is regular.
Similarly, in the brane world context, we find that the dS invariant vacuum
generates \tmn divergent everywhere when the lowest lying mode becomes
massless except for massless minimal coupling case. A simple extension of the
AF vacuum to the present case avoids this global divergence, but \tmn remains
to be divergent along a timelike axis in the bulk. In this case, singularities
also appear along the light cone emanating from the origin in the bulk,
although they are so mild that \tmn stays finite except for non-minimal
coupling cases in four or six dimensions. We discuss implications of these
results for bulk inflaton models. We also study the evolution of the field
perturbations in dS brane world. We find that perturbations grow linearly with
time on the brane, as in the case of ordinary dS space. In the bulk, they are
asymptotically bounded.Comment: 20 pages. References adde
Thermal dependency of shell growth, microstructure, and stable isotopes in laboratory‐reared Scapharca broughtonii (Mollusca: Bivalvia)
We experimentally examined the growth, microstructure, and chemistry of shells of the bloody clam, Scapharca broughtonii (Mollusca: Bivalvia), reared at five temperatures (13, 17, 21, 25, and 29°C) with a constant pCO2 condition (∼450 μatm). In this species, the exterior side of the shell is characterized by a composite prismatic structure; on the interior side, it has a crossed lamellar structure on the interior surface. We previously found a negative correlation between temperature and the relative thickness of the composite prismatic structure in field‐collected specimens. In the reared specimens, the relationship curve between temperature and the growth increment of the composite prismatic structure was humped shaped, with a maximum at 17°C, which was compatible with the results obtained in the field‐collected specimens. In contrast, the thickness of the crossed lamellar structure was constant over the temperature range tested. These results suggest that the composite prismatic structure principally accounts for the thermal dependency of shell growth, and this inference was supported by the finding that shell growth rates were significantly correlated with the thickness of the composite prismatic structure. We also found a negative relationship between the rearing temperature and δ18O of the shell margin, in close quantitative agreement with previous reports. The findings presented here will contribute to the improved age determination of fossil and recent clams based on seasonal microstructural records
X-ray study of ferroic octupole order producing anomalous Hall effect
放射光でついに見えた磁気オクタポール --熱を電気に変える新たな担い手--. 京都大学プレスリリース. 2021-09-27.Recently found anomalous Hall, Nernst, magnetooptical Kerr, and spin Hall effects in the antiferromagnets Mn₃X (X = Sn, Ge) are attracting much attention for spintronics and energy harvesting. Since these materials are antiferromagnets, the origin of these functionalities is expected to be different from that of conventional ferromagnets. Here, we report the observation of ferroic order of magnetic octupole in Mn₃Sn by X-ray magnetic circular dichroism, which is only predicted theoretically so far. The observed signals are clearly decoupled with the behaviors of uniform magnetization, indicating that the present X-ray magnetic circular dichroism is not arising from the conventional magnetization. We have found that the appearance of this anomalous signal coincides with the time reversal symmetry broken cluster magnetic octupole order. Our study demonstrates that the exotic material functionalities are closely related to the multipole order, which can produce unconventional cross correlation functionalities
Randomised, multicentre prospective trial of transarterial chemoembolisation (TACE) plus sorafenib as compared with TACE alone in patients with hepatocellular carcinoma: TACTICS trial.
OBJECTIVE:This trial compared the efficacy and safety of transarterial chemoembolisation (TACE) plus sorafenib with TACE alone using a newly established TACE-specific endpoint and pre-treatment of sorafenib before initial TACE. DESIGN:Patients with unresectable hepatocellular carcinoma (HCC) were randomised to TACE plus sorafenib (n=80) or TACE alone (n=76). Patients in the combination group received sorafenib 400 mg once daily for 2-3 weeks before TACE, followed by 800 mg once daily during on-demand conventional TACE sessions until time to untreatable (unTACEable) progression (TTUP), defined as untreatable tumour progression, transient deterioration to Child-Pugh C or appearance of vascular invasion/extrahepatic spread. Co-primary endpoints were progression-free survival (PFS), which is not a conventional one but defined as TTUP, or time to any cause of death plus overall survival (OS). Multiplicity was adjusted by gatekeeping hierarchical testing. RESULTS:Median PFS was significantly longer in the TACE plus sorafenib than in the TACE alone group (25.2 vs 13.5 months; p=0.006). OS was not analysed because only 73.6% of OS events were reached. Median TTUP (26.7 vs 20.6 months; p=0.02) was also significantly longer in the TACE plus sorafenib group. OS at 1 year and 2 years in TACE plus sorafenib group and TACE alone group were 96.2% and 82.7% and 77.2% and 64.6%, respectively. There were no unexpected toxicities. CONCLUSION:TACE plus sorafenib significantly improved PFS over TACE alone in patients with unresectable HCC. Adverse events were consistent with those of previous TACE combination trials. TRIAL REGISTRATION NUMBER:NCT01217034
Thermal dependency of shell growth, microstructure, and stable isotopes in laboratory-reared Scapharca broughtonii (Mollusca: Bivalvia)
金沢大学国際基幹教育院 GS教育系We experimentally examined the growth, microstructure, and chemistry of shells of the bloody clam, Scapharca broughtonii (Mollusca: Bivalvia), reared at five temperatures (13, 17, 21, 25, and 29°C) with a constant pCO2 condition (∼450 μatm). In this species, the exterior side of the shell is characterized by a composite prismatic structure; on the interior side, it has a crossed lamellar structure on the interior surface. We previously found a negative correlation between temperature and the relative thickness of the composite prismatic structure in field-collected specimens. In the reared specimens, the relationship curve between temperature and the growth increment of the composite prismatic structure was humped shaped, with a maximum at 17°C, which was compatible with the results obtained in the field-collected specimens. In contrast, the thickness of the crossed lamellar structure was constant over the temperature range tested. These results suggest that the composite prismatic structure principally accounts for the thermal dependency of shell growth, and this inference was supported by the finding that shell growth rates were significantly correlated with the thickness of the composite prismatic structure. We also found a negative relationship between the rearing temperature and δ18O of the shell margin, in close quantitative agreement with previous reports. The findings presented here will contribute to the improved age determination of fossil and recent clams based on seasonal microstructural records. Key Points: Thermal plasticity of shell microstructural formation was examined Relative volume of composite prismatic structure was greatest at cooler temperature Growth rates were correlated with volume of composite prismatic structure © 2015. American Geophysical Union. All Rights Reserved
Brane Big-Bang Brought by Bulk Bubble
We propose an alternative inflationary universe scenario in the context of
Randall-Sundrum braneworld cosmology. In this new scenario the existence of
extra-dimension(s) plays an essential role. First, the brane universe is
initially in the inflationary phase driven by the effective cosmological
constant induced by small mismatch between the vacuum energy in the
5-dimensional bulk and the brane tension. This mismatch arises since the bulk
is initially in a false vacuum. Then, the false vacuum decay occurs, nucleating
a true vacuum bubble with negative energy inside the bulk. The nucleated bubble
expands in the bulk and consequently hits the brane, bringing a hot big-bang
brane universe of the Randall-Sundrum type. Here, the termination of the
inflationary phase is due to the change of the bulk vacuum energy. The bubble
kinetic energy heats up the universe. As a simple realization, we propose a
model, in which we assume an interaction between the brane and the bubble. We
derive the constraints on the model parameters taking into account the
following requirements: solving the flatness problem, no force which prohibits
the bubble from colliding with the brane, sufficiently high reheating
temperature for the standard nucleosynthesis to work, and the recovery of
Newton's law up to 1mm. We find that a fine tuning is needed in order to
satisfy the first and the second requirements simultaneously, although, the
other constraints are satisfied in a wide range of the model parameters.Comment: 20pages, 5figures, some references added, the previous manuscript has
been largely improve
Final Results of TACTICS: A Randomized, Prospective Trial Comparing Transarterial Chemoembolization Plus Sorafenib to Transarteria Chemoembolization Alone in Patients with Unresectable Hepatocellular Carcinoma
IntroductionSeveral clinical trials comparing the efficacy and safety of transarterial chemoembolization (TACE) plus molecular-targeted agents versus TACE alone revealed no clinical benefits in progression-free survival (PFS) or overall survival (OS). Here, we report the final OS analysis from the TACTICS trial, which previously demonstrated significant improvement in PFS with TACE plus sorafenib in patients with unresectable hepatocellular carcinoma (HCC) (NCT01217034).MethodsPatients with unresectable HCC were randomized to a TACE plus sorafenib group (N = 80) or a TACE alone group (N = 76). Patients in the combination treatment group received sorafenib 400 mg once daily for 2-3 weeks before TACE, followed by 800 mg once daily during on-demand conventional TACE sessions until time to untreatable progression. In this trial, TACE-specific PFS was used. TACE-specific PFS is defined as the time from randomization to progressive disease (PD) or death from any cause, and PD was defined as untreatable progression, caused by the inability of a patient to further receive or benefit from TACE for reasons that include intrahepatic tumor progression (25% increase vs. baseline) according to response evaluation criteria in cancer of the liver, the detection of extrahepatic spread, vascular invasion, or transient deterioration of liver function to Child-Pugh C after TACE.ResultsAt the cut-off date of July 31, 2020, 131 OS events were observed. The median OS was 36.2 months with TACE plus sorafenib and 30.8 months with TACE alone (hazard ratio [HR] = 0.861; 95% confidence interval [CI], 0.607-1.223; p = 0.40, ΔOS, 5.4 months). The updated PFS was 22.8 months with TACE plus sorafenib and 13.5 months with TACE alone (HR = 0.661; 95% CI, 0.466-0.938; p = 0.02). Post-trial treatments with active procedures/agents were received by 47 (58.8%) patients in the TACE plus sorafenib group and 58 (76.3%) in the TACE alone group (p = 0.01). In post hoc analysis, PFS and OS benefit were shown in HCC patients with tumor burden beyond up-to-7 criteria.ConclusionsIn TACTICS trial, TACE plus sorafenib did not show significant OS benefit over TACE alone; however, clinical meaningful OS prolongation and significantly improved PFS was observed. Thus, the TACE plus sorafenib can be considered a choice of treatment in intermediate-stage HCC, especially in patients with high tumor burden. Trial Registration: NCT01217034
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