Surrogate Test to Distinguish between Chaotic and Pseudoperiodic Time Series

In this communication a new algorithm is proposed to produce surrogates for pseudoperiodic time series. By imposing a few constraints on the noise components of pseudoperiodic data sets, we devise an effective method to generate surrogates. Unlike other algorithms, this method properly copes with pseudoperiodic orbits contaminated with linear colored observational noise. We will demonstrate the ability of this algorithm to distinguish chaotic orbits from pseudoperiodic orbits through simulation data sets from theR\"{o}ssler system. As an example of application of this algorithm, we will also employ it to investigate a human electrocardiogram (ECG) record.Comment: Accepted version, to appear in Phys. Rev.

Highly Nonlinear Liquid Surface Waves in the Dynamics of the Fluid Balancer

AbstractThis paper is concerned with the dynamics of a cylindrical vessel containing a small amount of liquid which, during rotation, is spun out to form a thin liquid layer on the outermost inner surface of the vessel. The liquid is able to counteract unbalanced mass in an elastically mounted rotor. Hence the name ‘fluid balancer’. The paper discusses the equations of motion for the coupled fluid-structure system, their solution in terms of a perturbation method, and how they can explain the working principle of the fluid balancer

Networks with time structure from time series

We propose a method of constructing a network, in which its time structure is directly incorporated, based on a deterministic model from a time series. To construct such a network, we transform a linear model containing terms with different time delays into network topology. The terms in the model are translated into temporal nodes of the network. On each link connecting these nodes, we assign a positive real number representing the strength of relationship, or the "distance," between nodes specified by the parameters of the model. The method is demonstrated by a known system and applied to two actual time series.Comment: 15 pages, 5 figures, accepted to be published in Physica

新しい概念に基づくダンパの開発 : 柔軟液体ダンパの発想と研究開発

A new type of damper called "flexible liquid damper" is being developed. This damper is composed of a flexible ball partially filled with liquid. The important feature of this damper is the surface of the ball moves with the motion of the attached structure followed by the motion of the fluid inside the ball. This fluid-motion gives much energy dissipating effect, which results to a big damping ratio. In this paper, it is introduced how to be developed, and the basic trend of the damper is introduced by shaking tests, both by a pricking and by a shaker test. To compare with the dynamic damper, an analytical explanation is tried, but it is not enough to express the damping value of this damper only with the mechanism of the dynamic damper. It is supposed to have another effect by the fluid motion

ABA signaling converts stem cell fate by substantiating a tradeoff between cell polarity, growth and cell cycle progression and abiotic stress responses in the moss Physcomitrium patens

Abscisic acid (ABA)-mediated abiotic stress tolerance causes plant growth inhibition. Under such stress conditions, some mosses generate de novo stress-resistant stem cells, also called brood cells or brachycytes, that do not exist under normal conditions. However, the cell physiological basis of the growth inhibition and the stem cell formation is not well understood. Here, we show that the ABA-induced growth inhibition of the moss Physcomitrium patens apical protonemal cells (protonemal stem cells) is mediated through a shift from asymmetric to symmetric cell division. This change of the cell division mode, and consequently change of stem cell activity, is substantiated by dampening cell polarity and cell proliferative activity through the altered distribution of cytoskeletal elements, the mitotic spindle and the vacuole, which results in the production of stress-resistant stem cells. Alteration of the cell physiological data is supported by the results of RNAseq analysis indicating rapid changes in both cell polarity and cell cycle regulation, while long-term treatments with ABA for 5 to 10 days impact mainly the transcriptional and translational regulation. The regulation of cell polarity and cell cycle genes suggests growth arrest mediated by small GTPases (ROPs) and their guanine exchange factors (ROPGEFs) and by cyclin and cyclin-dependent-kinase complex, respectively. Our data suggest that a tradeoff relationship between growth ability and abiotic stress response in the moss is substantiated by ABA signaling to suppress cell polarity and asymmetric cell growth and may play a pivotal role in stem cell fate conversion to newly produced stress-resistant stem cells