16 research outputs found
Distance determination of molecular clouds in the 1st quadrant of the Galactic plane using deep learning : I. Method and Results
Machine learning has been successfully applied in varied field but whether it
is a viable tool for determining the distance to molecular clouds in the Galaxy
is an open question. In the Galaxy, the kinematic distance is commonly employed
as the distance to a molecular cloud. However, there is a problem in that for
the inner Galaxy, two different solutions, the ``Near'' solution, and the
``Far'' solution, can be derived simultaneously. We attempted to construct a
two-class (``Near'' or ``Far'') inference model using a Convolutional Neural
Network (CNN), a form of deep learning that can capture spatial features
generally. In this study, we used the CO dataset toward the 1st quadrant of the
Galactic plane obtained with the Nobeyama 45-m radio telescope (l = 62-10
degree, |b| < 1 degree). In the model, we applied the three-dimensional
distribution (position-position-velocity) of the 12CO (J=1-0) emissions as the
main input. The dataset with ``Near'' or ``Far'' annotation was made from the
HII region catalog of the infrared astronomy satellite WISE to train the model.
As a result, we could construct a CNN model with a 76% accuracy rate on the
training dataset. By using the model, we determined the distance to molecular
clouds identified by the CLUMPFIND algorithm. We found that the mass of the
molecular clouds with a distance of < 8.15 kpc identified in the 12CO data
follows a power-law distribution with an index of about -2.3 in the mass range
of M >10^3 Msun. Also, the detailed molecular gas distribution of the Galaxy as
seen from the Galactic North pole was determined.Comment: 29 pages, 12 figure
In Situ Observation of Cu2+ Concentration Profile During Cu Dissolution in Magnetic Field
It is important to understand and control corrosion in very small parts. For this purpose, in situ observation of corrosion reactions is necessary. Magnetic fields offer a new way of influencing corrosion reactions. We have investigated the dissolution of a Cu anode in a magnetic field using a holographic laser interferometric microscope. The microscope enables us to quantify the growth of the diffusion layer and the variation in Cu2+ concentration in the vicinity of the electrode. By sandwiching the anode between two doughnut-shaped neodymium magnets, the increase in the surface concentration caused by dissolution is remarkably suppressed, whereas the thickness of the diffusion layer is barely affected. The present results support the hypothesis that mass transport in enhanced in the magnetic field
In situ observation of the formation and relaxation processes of concentration gradients in a lithium bis(fluorosulfonyl) amide–tetraglyme solvate ionic liquid using digital holographic interference microscopy
Next-generation Li-ion batteries (LIBs) require fast charge–discharge operations, during which a steep concentration gradient (CG) is formed between the two electrodes. The formation of a concentration profile between the electrodes in a LIB with a solvate ionic liquid is observed at a distance of less than 1 mm using holographic interferometry. This in situ technique enables the visualization of concentration profile formation near both electrodes during electrolysis, which relaxes after the electrolysis is stopped. The diffusion coefficients near both the electrodes are calculated from the concentrations of transient species near the electrode surfaces. The diffusion coefficient is smaller on the anode side of the cell than on the cathode side owing to the viscosity of the electrolyte in the diffusion layer. This viscosity effect may have caused the concentration profile to become asymmetrical during the relaxation of the CG
In Situ Measurement of Al3+ Concentration Profile during Al Anodization using Digital Holographic Interferometric Microscope
In this study, the ionic mass transfer phenomenon of Al3+ in a sulfuric acid (pH 1) accompanying the anodization of an Al electrode was investigated using a digital holographic interferometric microscope. The anodization of an Al electrode is very popular technique to functionalize Al plates however, the anodization mechanism in the initial stage has not yet been understood, especially for the ionic mass transfer phenomenon. The investigation revealed the refractive index profile corresponding to the Al3+ concentration profile in the electrolyte. The Al3+ concentration on the electrode surface increased because of the Al dissolution in the initial stage of the anodization, and the thickness of the diffusion layer was proportional to the square root of time. The Al3+ surface concentration started to decrease after approximately 20 s probably because the Al dissolution reaction was hindered, and the Al oxide layer formation progressed. Additionally, ex situ scanning electron microscopy observation showed pores on the electrode surface at 80 s, which indicated that the pore formation was initiated from approximately 40 s with the progress of the oxide film formation. This research must be a steppingstone in order to understand the mechanism of anodization of Al
Activation of Invariant Natural Killer T Cells by alpha-Galactosylceramide Attenuates the Development of Angiotensin II-Mediated Abdominal Aortic Aneurysm in Obese ob/ob Mice
The infiltration and activation of macrophages as well as lymphocytes within the aorta contribute to the pathogenesis of abdominal aortic aneurysm (AAA). Invariant natural killer T (iNKT) cells are unique subset of T lymphocytes and have a crucial role in atherogenesis. However, it remains unclear whether iNKT cells also impact on the development of AAA. Ob/ob mice were administered angiotensin II (AngII, 1,000 ng/kg/min) or phosphate-buffered saline (PBS) by osmotic minipumps for 4 weeks and further divided into 2 groups; alpha-galactosylceramide (alpha GC; PBS-alpha GC; n = 5 and AngII-alpha GC; n = 12), which specifically activates iNKT cells, and PBS (PBS-PBS; n = 10, and AngII-PBS; n = 6). Maximal abdominal aortic diameter was comparable between PBS-PBS and PBS-alpha GC, and was significantly greater in AngII-PBS than in PBS-PBS. This increase was significantly attenuated in AngII-alpha GC without affecting blood pressure. alpha GC significantly enhanced iNKT cell infiltration compared to PBS-PBS. The ratio of F4/80-positive macrophages or CD3-positive T lymphocytes area to the lesion area was significantly higher in AngII-PBS than in PBS-PBS, and was significantly decreased in AngII-alpha GC. Gene expression of M2-macrophage specific markers, arginase-1 and resistin-like molecule alpha, was significantly greater in aortic tissues from AngII-alpha GC compared to AngII-PBS 1 week after AngII administration, and this increase was diminished at 4 weeks. Activation of iNKT cells by alpha GC can attenuate AngII-mediated AAA in ob/ob mice via inducing anti-inflammatory M2 polarized state. Activation of iNKT cells by the bioactive lipid alpha GC may be a novel therapeutic target against the development of AAA
AST-120 ameliorates lowered exercise capacity and mitochondrial biogenesis in the skeletal muscle from mice with chronic kidney disease via reducing oxidative stress
Background. Exercise capacity and quality of life are markedly impaired in chronic kidney disease (CKD). Increased plasma uremic toxins such as indoxyl sulfate (IS), which induce oxidative stress, may be involved in this process. An oral adsorbent, AST-120, can reduce circulating IS, however, its effects on skeletal muscle and exercise capacity have not been investigated in CKD. Methods. Subtotal-nephrectomy or sham operation was performed in 8-week-old C57BL/6J mice. They were divided into two groups with or without 8% (w/w) of AST-120 in standard diet for 20 weeks. Sham, Sham + AST-120, CKD and CKD + AST-120 (n = 12, each group) were studied. We also conducted a C2C12 cell culture study to determine the direct effects of IS on oxidative stress. Results. Plasma IS levels were significantly increased in CKD compared with Sham (1.05 +/- 0.11 versus 0.21 +/- 0.03 mg/dL, P < 0.05), which was significantly ameliorated in CKD + AST120 (0.41 +/- 0.06 mg/dL). The running distance to exhaustion determined by treadmill tests was significantly reduced in CKD compared with Sham (267 +/- 17 versus 427 +/- 36 m, P < 0.05), and this reduction was also significantly ameliorated in CKD + AST-120 (407 +/- 38 m) without altering skeletal muscle weight. Citrate synthase activity and mitochondrial biogenesis gene were downregulated, and superoxide production was significantly increased in the skeletal muscle from CKD, and these changes were normalized in CKD + AST-120. Incubation of C2C12 cells with IS significantly increased NAD(P) H oxidase activity. Conclusions. The administration of AST-120 improved exercise capacity and mitochondrial biogenesis of skeletal muscle via reducing oxidative stress. AST-120 may be a novel therapeutic agent against exercise intolerance in CKD