176 research outputs found
Development of a UAV-mounted Light Source for Fluorescence Detector Calibration of the Telescope Array Experiment
ArticleThe Physical Society of Japanjournal articl
Maintenance of GLUT4 expression in smooth muscle prevents hypertension‐induced changes in vascular reactivity
Previous studies have shown that expression of GLUT4 is decreased in arterial smooth muscle of hypertensive rats and mice and that total body overexpression of GLUT4 in mice prevents enhanced arterial reactivity in hypertension. To demonstrate that the effect of GLUT4 overexpression on vascular responses is dependent on vascular smooth muscle GLUT4 rather than on some systemic effect we developed and tested smooth‐muscle‐specific GLUT4 transgenic mice (SMG4). When made hypertensive with angiotensin II, both wild‐type and SMG4 mice exhibited similarly increased systolic blood pressure. Responsiveness to phenylephrine, serotonin, and prostaglandin F2α was significantly increased in endothelium‐intact aortic rings from hypertensive wild‐type mice but not in aortae of SMG4 mice. Inhibition of Rho‐kinase equally reduced serotonin‐stimulated contractility in aortae of hypertensive wild‐type and SMG4‐mice. In addition, acetylcholine‐stimulated relaxation was significantly decreased in aortic rings of hypertensive wild‐type mice, but not in rings of SMG4 mice. Inhibition of either prostacylin receptors or cyclooxygenase‐2 reduced relaxation in rings of hypertensive SMG4 mice. Inhibition of cyclooxygenase‐2 had no effect on relaxation in rings of hypertensive wild‐type mice. Cyclooxygenase‐2 protein expression was decreased in hypertensive wild‐type aortae but not in hypertensive SMG4 aortae compared to nonhypertensive controls. Our results demonstrate that smooth muscle expression of GLUT4 exerts a major effect on smooth muscle contractile responses and endothelium‐dependent vasorelaxation and that normal expression of GLUT4 in vascular smooth muscle is required for appropriate smooth muscle and endothelial responses.e12299In the smooth muscle of aortae of hypertensive mice, expression of GLUT4 is decreased. Maintenance of aortic smooth muscle GLUT4 expression prevents hypertension‐mediated changes in vasomotor response. These effects include decreasing/preventing endothelial dysfunction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110755/1/phy212299.pd
Glacial fjord environment and ecosystem reconstructed from sediments deposited in Bowdoin Fjord, northwestern Greenland.
The Tenth Symposium on Polar Science/Ordinary sessions: [OG] Polar Geosciences, Wed. 4 Dec. / 3F Seminar room, National Institute of Polar Researc
Magnetic anisotropy driven by ligand in 4d transition metal oxide SrRuO3
The origin of magnetic anisotropy in magnetic compounds is a longstanding
issue in solid state physics and nonmagnetic ligand ions are considered to
contribute little to magnetic anisotropy. Here, we introduce the concept of
ligand driven magnetic anisotropy in a complex transition-metal oxide. We
conducted X ray absorption and X ray magnetic circular dichroism spectroscopies
at the Ru and O edges in the 4d ferromagnetic metal SrRuO3. Systematic
variation of the sample thickness in the range below 10 nm allowed us to
control the localization of Ru 4d t2g states, which affects the magnetic
coupling between the Ru and O ions. We found that the orbital magnetization of
the ligand induced via hybridization with the Ru 4d orbital determines the
magnetic anisotropy in SrRuO3
Higher-order modulations in the skyrmion-lattice phase of CuOSeO
Using small angle neutron scattering, we have investigated higher-order peaks
in the skyrmion-lattice phase of CuOSeO, in which two different
skyrmion lattices, SkX1 and SkX2, are known to form. For each skyrmion-lattice
phase, we observed two sets of symmetrically inequivalent peaks at the
higher-order-reflection positions with the indices and . Under
the condition where the SkX1 and SkX2 coexist, we confirmed the absence of the
scattering at positions combining reflections from the two phases,
indicating a significantly weak double-scattering component. Detailed analysis
of the peak profile, as well as the temperature and magnetic-field dependence
of the peak intensity, also supports the intrinsic higher-order modulation
rather than the parasitic double scattering. The two higher-order modulations
show contrasting magnetic-field dependence; the former increases as the
field is increased, whereas the latter decreases. This indicates that,
in CuOSeO, skyrmions are weakly distorted, and the distortion is
field-dependent in a way that the dominant higher-order modulation switches
from to under field. Monte Carlo simulations under sweeping
external magnetic field qualitatively reproduce the observed magnetic-field
dependence, and suggests that the higher-order modulations correspond to the
superlattices of weak swirlings appearing in the middle of the original
triangular-latticed skyrmions.Comment: 13 pages, 14 figure
Task-adaptive physical reservoir computing
Reservoir computing is a neuromorphic architecture that may offer viable solutions to the growing energy costs of machine learning. In software-based machine learning, computing performance can be readily reconfigured to suit different computational tasks by tuning hyperparameters. This critical functionality is missing in 'physical' reservoir computing schemes that exploit nonlinear and history-dependent responses of physical systems for data processing. Here we overcome this issue with a 'task-adaptive' approach to physical reservoir computing. By leveraging a thermodynamical phase space to reconfigure key reservoir properties, we optimize computational performance across a diverse task set. We use the spin-wave spectra of the chiral magnet Cu2OSeO3 that hosts skyrmion, conical and helical magnetic phases, providing on-demand access to different computational reservoir responses. The task-adaptive approach is applicable to a wide variety of physical systems, which we show in other chiral magnets via above (and near) room-temperature demonstrations in Co8.5Zn8.5Mn3 (and FeGe)
Task-adaptive physical reservoir computing
Reservoir computing is a neuromorphic architecture that potentially offers
viable solutions to the growing energy costs of machine learning. In
software-based machine learning, neural network properties and performance can
be readily reconfigured to suit different computational tasks by changing
hyperparameters. This critical functionality is missing in ``physical"
reservoir computing schemes that exploit nonlinear and history-dependent memory
responses of physical systems for data processing. Here, we experimentally
present a `task-adaptive' approach to physical reservoir computing, capable of
reconfiguring key reservoir properties (nonlinearity, memory-capacity and
complexity) to optimise computational performance across a broad range of
tasks. As a model case of this, we use the temperature and magnetic-field
controlled spin-wave response of CuOSeO that hosts skyrmion, conical
and helical magnetic phases, providing on-demand access to a host of different
physical reservoir responses. We quantify phase-tunable reservoir performance,
characterise their properties and discuss the correlation between these in
physical reservoirs. This task-adaptive approach overcomes key prior
limitations of physical reservoirs, opening opportunities to apply
thermodynamically stable and metastable phase control across a wide variety of
physical reservoir systems, as we show its transferable nature using
above(near)-room-temperature demonstration with CoZnMn
(FeGe).Comment: Main manuscript: 14 pages, 5 figures. Supplementary materials: 13
pages, 10 figure
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