Sophia University

About: Sophia University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Nonlinear system & Catalysis. The organization has 4986 authors who have published 7657 publications receiving 106567 citations. The organization is also known as: Jōchi Daigaku.

Isolation and partial characterization of a spawning female-specific substance in the teleost, Oryzias latipes

Abstract: A “spawning female-specific substance” (SF substance) [Hamazaki et al. (1985) J. Exp. Zool., 235:269–279] was isolated from the ascites fluid of the estrogen-fed (EF) male or nonspawning female fish, Oryzias latipes, by gel filtration chromatography, followed by high-performance ion-exchange liquid chromatography (HPLC). Biochemical analyses revealed that the SF substance was a glycoprotein that contained 3.01% carbohydrates and showed 49,000 molecular weight (mw) on SDS-PAGE. Amino acid composition and the carbohydrate content of the SF substance were similar to those of the glycoproteins, F1 and F2, which were purified from the hatching enzyme digest of the inner layer (zona interna) of egg chorion (egg envelope). The inner layer of chorion from ovarian egg (oocyte) was separable into three different glycoproteins, ZI-1 (mw 76,000), Z1-2 (mw 74,000), and ZI-3 (mw 49,000) on SDS-PAGE. The major glycoprotein, ZI-3, was found to show the mw and amino acid composition that were almost identical to those of the purified SF substance. These results indicate that a substance that is almost the same as the major component glycoprotein of the inner layer of chorion, in terms of the biochemical as well as immunological properties, is present out-side the ovary and is produced in the liver of the spawning female fish as well as the EF fish.

Problems of impedance cardiography.

Abstract: Various electrical-impedance methods have been proposed for the measurement of haemodynamic parameters noninvasively. For example, an impedance method is proposed for the measurement of cardiac output from the skin surface and is called impedance cardiography. However, there are many problems in the application of the impedance technique for the noninvasive measurement of haemodynamic parameters. One of them is the complicated structure of organs in the body. Another is the anomalous electrical properties of tissues. For these reasons, it is very difficult to obtain exact information about haemodynamics from the waveforms measured by the impedance cardiograph, in spite of the fact that the waveforms include much useful information. We can get useful information, if the relationships between the waveforms and the biomedical events in the subject are understood. In this paper, the relationships between the waveforms and the circulation of the blood are discussed theoretically and experimentally. The effects of the complicated structure of the organs and the anomalous electrical properties of tissues upon the waveforms are also discussed both theoretically and experimentally. For the analysis of the waveforms, it is very important to discuss (a) equipotential lines and potential distribution on the thorax, (b) the impedance or admittance between a pair of electrodes, (c) impedance or admittance changes due to blood circulation, (d) waveforms due to the pulsatile blood flow and (e) the effects of the complicated structure of organs upon the waveforms. From our results, it is concluded that: (a) the waveforms measured by an impedance cardiograph are affected not only by the change of blood volume in the aorta but also by that in various organs such as the heart and lungs. (b) the impedances measured by a pair of small electrodes separated by a short distance give useful information about the region in the vicinity of the electrodes (c) much valuable information will be available, if the relationships between the measurement results and the pulsatile blood flow are understood, and (d) by choosing an appropriate electrode arrangement, we may get much useful information about the blood circulation in the organs we want to investigate

Policy Iteration Approach to Control Residual Gas Fraction in IC Engines Under the Framework of Stochastic Logical Dynamics

Abstract: This brief investigates the cycle-to-cycle transient behavior of the residual gas fraction (RGF) in terms of systems theory and proposes a multivalued logic-based optimal control strategy for the attenuation of RGF fluctuation. First, an in-cylinder pressure-based method for measuring RGF is provided, and the stochastic properties of the RGF are examined based on statistical data obtained by conducting experiments on a full-scale internal combustion engine test bench. Based on the observation of the experiment, a stochastic logical transient model is proposed to represent the cycle-to-cycle transient behavior of the RGF. Then, an optimal feedback control law, which targets the rejection of the RGF fluctuation, is derived using the policy iteration algorithm. Finally, the experimental result is demonstrated to show the effectiveness of the proposed optimal control law.