No abstract

No abstract

No abstract

No abstract

The master equation for the reversible reaction A + A ⇀ ↽ 0 is considered in Poisson representation, where it is equivalent to a Langevin equation with imaginary noise for a complex stochastic variable φ. Such Langevin equations appear quite generally in field-theoretic treatments of reaction-diffusion problems. For this example we study the probability flow in the complex φ plane both analytically and by simulation. We show that this flow has various curious features that must be expected to occur similarly in other Langevin equations associated with reaction-diffusion problems.

Since BALCKE (1) first named the tetrads-forming cocci in spoiled beer as Pediococcus ceyevisiae, various specific names (2,3,4, 5, 6, 7, 8, 9, 10, 11,12) have been applied by many investigators to those strains of pediococci associated with brewery products.In recent years, PEDERSON (13, 14) recognized the importance of pediococci in fermenting vegetables such as sauerkraut and pickles, and attempted the classification of many pediococci. According to the opinion of PEDERSON appearing in BERGEY'S Manual (15), the genus Pediococcus is included in the family Lactobacillaceae and is summarized into two species : Pediococcus ceyevisiae BALCKE and Pediococcus acidilactici LINDNER. The former species which is capable of growing in beer and hopped wort includes pediococci distributing in beer as well as in fermenting vegetables. But this opinion is still a debatable problem and is not yet settled today.More recently, two curious species were described by Japanese workers. One is mevalonic acid requiring strain, Pediococcus mevalovorus, which has been isolated by KITAHARA & NAKAGAWA (16) from beer, and the other is strongly halophilic Pediococcus soyae isolated from soy-mashes by SAKAGUCHI (17) and YAMAZATO (18) independently at almost the same time, which cannot be included into any of the above mentioned species.We have therefore attempted taxonomic studies on the pediococci isolated from mash, yeasts and beer including our unpublished strains and also on the authentic strains supplied by many investigators.As a conclusion, we have found that the pediococci growing in beer are quite different from those of fermenting vegetables in many taxonomic properties, and we wish to propose that the genus Pediococcus should at least be classified into five species, i.e., P. ceyevisiae, P. acidilactici, P. pentosaceus, P. halophilus and P. urinae-equi.The taxonomic properties of these species and the reason for classifying them into five species are described in herein as follows. EXPERIMENTAL 1. Strains Taxonomic studies have been made on the strains isolated by the * Asahi Breweries Co . Ltd., Tokyo. 95 96 A. NAKAGAWA and K. KITAHARA present authors, and those supplied by many investigators. These strains are described as follows. Strain No. Source § Acid sensitive group (Pediococcus urinae-equi & P. halophilus) *P . halophilus MEES (1934) .... P. hal..... anchovy (Tetracoccus No. 1 ORLA-JENSEN 1919) pickles *P . urinae-equi MEES (1934) .... P. u.e..... horse-urine Tetrakokken Stamm von S. STRESE & S. WINDIscH (1955) (19) .... beer, brewing .... C, F, T, Sp-2 & Sp-4 -water, horse-urine °A -38 , A-40, N-21 & A-28 isolated by A. NAKAGAWA & K. KITAHARA (1956) .... *P . soyae K. SAKAGUCHI (1958) .... d-2, d-8 & dl-2....

If spinodal decomposition is modeled by the Cahn-Hilliard (-Cook) equation, the effect of a uniform external force such as gravitation does not appear in the bulk phase kinetics. In contrast, in the Kawasaki exchange modeling of the local dynamics of binary alloys, this effect directly modifies the bulk phase kinetics. We resolve this paradox through the cell-dynamical-system modeling of the Kawasaki exchange dynamics. Its continuum version has turned out to be a modified Cahn-Hilliard equation already proposed by Langer et al. about ten years ago. We demonstrate some examples in which the correction to the Cahn-Hilliard equation is significant.

No abstract