Striatal-Inoculation of α-Synuclein Preformed Fibrils Aggravated the Phenotypes of REM Sleep without Atonia in A53T BAC-SNCA Transgenic Mice

Accumulation of α-synuclein (α-syn) is the pathological hallmark of α-synucleinopathy. Rapid eye movement (REM) sleep behavior disorder (RBD) is a pivotal manifestation of α-synucleinopathy including Parkinson’s disease (PD). RBD is clinically confirmed by REM sleep without atonia (RWA) in polysomnography. To accurately characterize RWA preceding RBD and their underlying α-syn pathology, we inoculated α-syn preformed fibrils (PFFs) into the striatum of A53T human α-syn BAC transgenic (A53T BAC-SNCA Tg) mice which exhibit RBD-like phenotypes with RWA. RWA phenotypes were aggravated by PFFs-inoculation in A53T BAC-SNCA Tg mice at 1 month after inoculation, in which prominent α-syn pathology in the pedunculopontine nucleus (PPN) was observed. The intensity of RWA phenotype could be dependent on the severity of the underlying α-syn pathology.     

Immittance converters suitable for power electronics

An immittance converter has fine performance in many power electronics applications. Its function is to convert voltage sources into current sources and current sources into voltage sources. The immittance converter has an input impedance that is proportional to the admittance of loads connected across output terminals. Therefore, in this converter, the output current is proportional to the input voltage and the input current is proportional to the output voltage. Consequently, it converts a constant voltage source into a constant current source and a constant current source into a constant voltage source. When an immittance converter operates at a resonant frequency and is inserted to high-frequency link systems, voltage source outputs turn into current source outputs and current source outputs turn into voltage source outputs. Some power electronics applications of this converter are photovoltaic inverters and dc-dc converters with constant current outputs. It is well known that a quarter-wavelength transmission line shows immittance conversion characteristics. However, it has a very long line length for its switching frequency (e.g., 20 kHz), and is not suitable for power electronics applications. Therefore we propose five immittance converters that consist of lumped L and C elements and show the immittance conversion characteristics at a resonant frequency. These immittance converters are much smaller and lighter than the transmission line. Their principles, basic circuits, and basic characteristics are described in this paper. We also evaluate their application to high-frequency link systems of power electronics. © 1998 Scripta Technica, Electr Eng Jpn, 124(2): 53–62, 1998     

Investigation of the factors affecting the limit of detection of laser-induced breakdown spectroscopy for surface inspection

Laser-induced breakdown spectroscopy(LIBS) was examined to detect a trace substance adhered onto Al alloys for the surface inspection of materials to be adhesively bonded. As an example of Si contamination, silicone oil was employed and sprayed onto substrates with a controlled surface concentration. LIBS measurements employing nanosecond UV pulses(λ?=?266 nm) and an off-axis emission collection system with different detecting heights were performed. Because surface contaminants are involved in the plasma formed by laser ablation of the substrates, the relative contribution of the surface contaminants and the substrates to the plasma emission could be changed depending on the conditions for plasma formation. The limit of detection(LOD) was evaluated under several detecting conditions for investigating the factors that affected the LOD. A significant factor was the standard deviation values of signal intensities obtained for the clean substrates. This value varied depending on the measurement conditions.For the Al alloy(A6061), the smallest LOD obtained was 0.529 μg?·?cm~(-2). Furthermore, an improved LOD(0.299 μg?·?cm~(-2)) was obtained for the Al alloy with a lower Si content.     

Field-emission characteristics of diamond-like amorphous carbon films deposited by mixed gas (N2 or H2) controlled i-C4H10 supermagnetron plasma

Diamond-like amorphous carbon (DAC) films were deposited for field-emission application using supermagnetron plasma by mixing N₂ or H₂ in i-C₄H₁₀ gas at the upper and lower electrode rf powers (UPRF/LORF) of 800 W/100-800 W. At an 800 W/800 W, the N₂ (0-80%) gas-mixed DAC films showed an emission threshold electric field (E_TH) of 19 V/μm. At the 800 W/100 W, the H₂ (20%) gas-mixed DAC film showed low E_TH's of 13 V/μm, respectively. The moderate reduction of CC and CN double bonds by the decrease of LORF from 800 W to 100 W was found to be effective to lower E_TH.     

An Efficient Support Vector Machine Learning Method with Second-Order Cone Programming for Large-Scale Problems

In this paper we propose a new fast learning algorithm for the support vector machine (SVM). The proposed method is based on the technique of second-order cone programming. We reformulate the SVM's quadratic programming problem into the second-order cone programming problem. The proposed method needs to decompose the kernel matrix of SVM's optimization problem, and the decomposed matrix is used in the new optimization problem. Since the kernel matrix is positive semidefinite, the dimension of the decomposed matrix can be reduced by decomposition (factorization) methods. The performance of the proposed method depends on the dimension of the decomposed matrix. Experimental results show that the proposed method is much faster than the quadratic programming solver LOQO if the dimension of the decomposed matrix is small enough compared to that of the kernel matrix. The proposed method is also faster than the method proposed in (S. Fine and K. Scheinberg, 2001) for both low-rank and full-rank kernel matrices. The working set selection is an important issue in the SVM decomposition (chunking) method. We also modify Hsu and Lin's working set selection approach to deal with large working set. The proposed approach leads to faster convergence. Rameswar Debnath is a Ph.D candidate at the University of Electro-Communications, Tokyo, Japan and also a lecturer of the Computer Science & Engineering Discipline at Khulna University, Bangladesh. He received the bachelor's degree in computer science and engineering from Khulna University in 1997 and masters of engineering degree in communication and systems from the University of Electro-Communications in 2002. His research interests include support vector machines, artificial neural networks, pattern recognition, and image processing. Masakazu Muramatsu is an associate professor of the Department of Computer Science at the University of Electro-Communications, Japan. He received a bachelor's degree from the University of Tokyo in 1989, master's degree in engineering from University of Tokyo in 1991, and Ph.D from the Graduate University for Advanced Studies in 1994. He was an assistant professor of the Department of Mechanical Engineering at Sophia University from 1994 to 2000, when he moved to the current university. His research interests include mathematical programming, second-order cone programming and its application to machine learning. Haruhisa Takahashi was born in Shizuoka Prefecture Japan, on March 31, 1952. He graduated from the University of Electro-Communications. He received the Dr Eng. degree from Osaka University. He was a faculty member of the Department of Computer Science and Engineering at Toyohashi University of Technology from 1980 to 1986. Since 1986, he has been with the University of Electro-Communications where he is currently professor of the Department of Information and Communication Engineering. He was previously engaged in the fields of nonlinear network theory, queueing theory and performance evaluation of communication systems. His current research includes learning machines, artificial neural networks, and cognitive science.     

Preparation of Inorganic Consolidated Body Using Aluminium Hydroxide Mechanically Activated by Dry Milling

Aluminium hydroxide (Al(OH)₃) was mechanically activated by dry milling. In order to develop an inorganic consolidated material, the structure and reactivity of milled Al(OH)₃ were investigated and consolidated bodies were prepared using the reaction between activated Al(OH)₃ and a potassium silicate solution. Milling up to 1 h apparently reduced the grain size and promoted amorphization, although milling longer than 2 h did not give a significant physical change. Milled Al(OH)₃ directly transformed to -Al₂O₃ around 270°C. The transformation temperature decreased with increasing milling time. The remarkable enhancement of the reactivity was attained. The reactivity of Al(OH)₃ milled for 2 h improved 1000 times more than that of as-received Al(OH)₃. The preforming paste, prepared with as-received Al(OH)₃, could not consolidate at room temperature without drying. On the other hand, for Al(OH)₃ milled for 2 h, the preforming paste consolidated in 10 min and the consolidated material showed much better resistance against water than that prepared with as-received Al(OH)₃. The possibility of a new inorganic consolidated material was suggested using the reaction between mechanically activated Al(OH)₃ and the potassium silicate solution.     

High Precision On‐Line Offset Correction for Motor Angle Sensors

In this paper, an angle detecting system is proposed that calculates the offset correction values for the sine and cosine signals of angle sensors. The offset correction values are calculated not from the offset errors of the sine and cosine signals but from the 1f angle error (the fundamental frequency component of the sine and cosine signals) of the angle signals. Therefore, the system can correct the 1f angle error even when the sine and cosine signals contain the double‐frequency components of the sine and cosine signals, as well as the dc offset errors. Moreover, it is possible to use low‐cost microcomputers with low computing speed, because the offset correction values are dc quantities.