Waseda University

About: Waseda University is a education organization based out in Tokyo, Japan. It is known for research contribution in the topics: Large Hadron Collider & Catalysis. The organization has 24220 authors who have published 46859 publications receiving 837855 citations. The organization is also known as: Waseda daigaku & Sōdai.

Analytical properties of ultradiscrete Burgers equation and rule-184 cellular automaton

Abstract: In this paper, we propose an ultradiscrete Burgers equation of which all the variables are discrete. The equation is derived from a discrete Burgers equation under an ultradiscrete limit and reduces to an ultradiscrete diffusion equation through the Cole-Hopf transformation. Moreover, it becomes a cellular automaton (CA) under appropriate conditions and is identical to rule-184 CA in a specific case. We show shock wave solutions and asymptotic behaviours of the CA exactly via the diffusion equation. Finally, we propose a particle model expressed by the CA and discuss a mean flux of particles.

Flow measurements via two-particle azimuthal correlations in Au + Au collisions √SNN = 130 GeV

Abstract: Two-particle azimuthal correlation functions are presented for charged hadrons produced in Au+Au collisions at the Relativistic Heavy Ion Collider (sqrt[sNN]=130 GeV). The measurements permit determination of elliptic flow without event-by-event estimation of the reaction plane. The extracted elliptic flow values (v2) show significant sensitivity to both the collision centrality and the transverse momenta of emitted hadrons, suggesting rapid thermalization and relatively strong velocity fields. When scaled by the eccentricity of the collision zone e, the scaled elliptic flow shows little or no dependence on centrality for charged hadrons with relatively low pT. A breakdown of this e scaling is observed for charged hadrons with pT >1.0 GeV/c.

Circadian profile of Per gene mRNA expression in the suprachiasmatic nucleus, paraventricular nucleus, and pineal body of aged rats

Abstract: Aging alters circadian components such as the free-running period, the day-to-night activity ratio and photic entrainment in behavioral rhythms, and 2-deoxyglucose uptakes and neuronal firing in the suprachiasmatic nucleus (SCN). A core clock mechanism in the mouse SCN appears to involve a transcriptional feedback loop in which Period (Per) and Cryptochrome (Cry) genes play a role in negative feedback. The circadian rhythm systems include photic entrainment, clock oscillation, and outputs of clock information such as melatonin production. In this experiment, we examined clock gene expression to determine whether circadian input, oscillation, and output are disrupted with aging. Circadian expression profiles of rPer1, rPer2, or rCry1 mRNA were very similar in the SCN, the paraventricular nucleus of the hypothalamus (PVN), and the pineal body of young and aged (22-26 months) rats. On the other hand, the photic stimulation-induced rapid expression of Per1 and Per2 in the SCN was reduced with aging. The present results suggest that the molecular mechanism of clock oscillation in the SCN, PVN, and pineal body is preserved against aging, whereas the impairment of Per1 induction in the SCN after light stimulation may result in impaired behavioral photic entrainment in aged rats.