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In a uniform layer consisting of a mixture of granular material and liquid, it is known that desiccation cracks exhibit various anisotropic patterns that depend on the nature of the shaking that the layer experienced before drying. The existence of this effect implies that information regarding the direction of shaking is retained as a kind of memory in the arrangements of granular particles. In this work we make measurements in paste composed of Lycopodium powder using microfocus x-ray computerized tomography ($\mu$CT) in order to investigate the three-dimensional arrangements of particles. We find shaking-induced anisotropic arrangements of neighboring particles and density fluctuations forming interstices mainly in the lower part of the layer. We compare the observed properties of these arrangements with numerical results obtained in the study of a model of non-Brownian particles under shear deformation. In the experimental system, we also observe crack tips in the $\mu$CT images and confirm that these cracks grow along interstices in the direction perpendicular to the initial shaking., Comment: 12 pages, 9 figures, published at Phys. Rev. E

application/pdf, The European Physical Journal B. 2021, 94, P.200(p1-9)

Beta-propeller protein-associated neurodegeneration (BPAN) is categorized in Neurodegeneration with brain iron accumulation. The clinical feature of BPAN is global developmental delay in early childhood, followed rapid progression of cognitive disfunction and parkinsonism in adulthood. This case was pointed out intellectual disability at the age of 9, followed left dominant progressive parkinsonism from the age of 31. Brain MRI showed the T1-weighted signal hyperintensity of the substantia nigra with a central band of hypointensity and the T2 star weighted image hypointensity of substantia nigra and globus pallidus presenting dominant at right side. DAT SPECT also showed specific binding ratio decreased dominant in right side. She was diagnosed BPAN based on her genetic test revealing a novel mutation (c.411dupT) in WDR45. No studies reported detailed parkinsonism like laterality in BPAN. This case indicates the left dominant parkinsonism was caused by right dominant iron deposition to substantia nigra and globus pallidus in view of MRI findings and DAT SPECT.

Beta-propeller protein-associated neurodegeneration (BPAN) is categorized in Neurodegeneration with brain iron accumulation. The clinical feature of BPAN is global developmental delay in early childhood, followed rapid progression of cognitive disfunction and parkinsonism in adulthood. This case was pointed out intellectual disability at the age of 9, followed left dominant progressive parkinsonism from the age of 31. Brain MRI showed the T

The size distributions of persons’ names, i.e., how many people share a certain name, obeys Zipf’s law in various countries or areas. There is, however, a regionality for each country or area, and ...

It is known that pastes of fine powder, for example those of clay, retain memory of shaking applied early in a drying process. This memory results in the appearance of anisotropic patterns of desiccation cracks after drying. In this work, we find a similar behavior in pastes consisting of large granular particles, specifically cornstarch and Lycopodium spores. Because of the large particle size, we were able to observe particle arrangements in Lycopodium paste with micro-focus X-ray computerized tomography ( $\mu$ CT). We prepared pastes consisting of Lycopodium particles and water. Agar was added to the paste in order to allow for solidification during a drying process. In these samples, we found statistical anisotropy induced by shaking applied early in the drying process. This anisotropy possesses a feature that was predicted on the basis of results obtained in previous experimental and theoretical studies.

デンプン－水混合物の乾燥過程における3次元柱状構造亀裂について数値的に調べた．混合物を応力場と含水量場をもつ弾性多孔性物質と仮定し，二つの場の時間発展をそれぞれバネネットワークモデルと水ポテンシャルを用いた現象論的なモデルで記述した．数値計算の結果，表面から内部に向かって進行する乾燥フロントをもつ含水量分布，およびそのフロントと共に成長する亀裂の角柱構造を再現した．柱の太さの粒直径依存性，深さと共に角柱構造が拡大する過程を調べた．また，破壊点が多角形の辺に沿って伝播する非一様な破壊過程を見つけた．亀裂が含水量場に与える影響および柱状節理との対比について議論した.

The structure and motion of a single interface exhibiting chaotic behavior are investigated in one-dimensional parametrically forced complex Ginzburg-Landau equation. Several kinds of interfaces are classified by their dynamical behavior connected with the symmetries.

The motion of bouncing rigid line segment which iterates free-falls and collisions with a flat smooth floor is investigated as a model of coin tossing process. With suitable assumptions, a map from initial conditions to the final outcome, "Head" or "Tail" is numerically obtained. The basin structure is analyzed from the viewpoint of the length scale and the continuity. The origin of probability is considered in connection with the basin structure.

We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns. published

The aggregation process of granules driven by the motion of water-air fronts in the drying process of two-dimensional wet granular systems is experimentally studied. The fronts and aggregated granules interact with each other during this drying, and a labyrinthine pattern is formed as a result. A qualitative framework of the pattern formation is given, and topological and metrical properties of the pattern are also discussed.

We analyzed the spatio-temporal structure of hooded gull flocks with a portable stereo camera system. The 3-dimensional positions of individuals were reconstructed from pairs of videos. The motions of each individual were analyzed, and both gliding and flapping motions were quantified based on the velocity time series. We analyzed the distributions of the nearest neighbor’s position in terms of coordinates based on each individual’s motion. The obtained results were consistent with the aerodynamic interaction between individuals. We characterized the leader-follower relationship between individuals by a delay time to mimic the direction of a motion. A relation between the delay time and a relative position was analyzed quantitatively, which suggested the basic properties of the formation flight that maintains order in the flock.

Globally coupled activator-inhibitor systems are studied as a model of the regulation of cell proportion in biological differentiation. Formation and destabilization of one- and two-cluster states are predicted analytically. Numerical simulations show that the proportion of units in clusters falls within a finite range determined by the initial conditions.

Oscillating interfaces are found in the one-dimensional complex Ginzburg-Landau equation subject to a periodic force. By introducing a suitable section in the phase space, it is shown that the oscillation starts with a Hopf bifurcation and that subsequent bifurcations lead to various motions of interface

A method for estimating a period of unstable periodic solutions is suggested in continuous dissipative chaotic dynamical systems. The measurement of a minimum distance between a reference state and an image of transformation of it exhibits a characteristic structure of the system, and the local minima of the structure give candidates of period and state of corresponding symmetric solutions. Appropriate periods and initial states for the Newton method are chosen efficiently by setting a threshold to the range of the minimum distance and the period.

On the basis of topological arguments, it is shown that phase jump lines arise in two-dimensional cellular patterns. A phase jump line either ends at a phase singularity with a half-integer topological charge or it has no endpoints. As a simple model equation which exhibits such lines, a set of amplitude equations describing resonant interaction between two modes with wave numbers k and 2k is considered. Numerical simulations of the model equations show that these lines are spontaneously formed in ordering process of cellular structures.

Coupled complex Ginzburg-Landau equations representing interacting oscillatory fields were found to sustain a localized target pattern. The pattern emits phase waves from its center down to the boundary of localized structure. For a certain parameter range; we found analytically a one-dimensional solution which consists of a pair of localized waves, one of which is the so-called hole solution. Our computer simulation confirmed the existence of such a solution, but even for wider range of parameter values than it expected from the analytical calculations.

The formation of three-dimensional prismatic cracks in the drying process of starch-water mixtures is investigated numerically. We assume that the mixture is an elastic porous medium which possesses a stress field and a water content field. The evolution of both fields are represented by a spring network and a phenomenological model with the water potential, respectively. We find that the water content distribution has a propagating front which is not explained by a simple diffusion process. The prismatic structure of cracks driven by the water content field is observed. The depth dependence and the coarsening process of the columnar structure are also studied. The particle diameter dependence of the scale of the columns and the effect of the crack networks on the dynamics of the water content field are also discussed., 12 pages, 14 figures

Collective behavior of active elements inspired by mass of biological organisms such as social insects is addressed. Here, task allocation phenomena are treated from the viewpoint of proportion regulation of population between different states. Using a dynamical potential model consisting of elements and external "stock materials", adaptability against various disturbances is numerically studied. The performance of the proposed model is also examined by the experiments with real robots system.

This paper reports collective behaviors of multirobot system with simple dynamics and interactions. The model for collective motion is described by fundamental kinetics and the dynamics of the heading which each element has as a degree of freedom. Firstly, we shows the system based on this model realizes various types of behavior according to the set of parameters in the model, which resembles to the behavior of livings such as fish, birds and small insects. Next, we refer to the behavior of the modified model improving the anisotropy of the interaction force. Especially, we discuss the characteristic of linear formation which is obtained by modifying the term of optimal distance between neighbors. Performance of the model is examined by both computer simulation and robot experiments.

Structures and motions of a single interface exhibiting chaotic behavior are studied in the one-dimensional parametrically forced complex Ginzburg-Landau equation. There exist two kinds of chaotic interfaces whose differences are characterized by their chiral symmetry and the diffusivity of their motion. The transition between these behaviors is also investigated from the viewpoint of singularities of several dynamical variables, such as the diffusion constant, the resident time to each state, and the maximum trapping time to the unstable solution.

Division of labor performed by social insects, such as ants and bees, is one of the most advanced functions that they have evolved. Although individual insects have the same inheritance, they are divided into certain groups in which they play specialized roles. For effective performance, the groups exhibit proportional regulation of population, which implies regulating their population to maintain their proportion; further the proportion of each group is regulated against external disturbances without aid from a special individual. In a multi-robot system, the division of labor is one of the most attractive and useful propositions. This paper addresses the proportion regulation of population in a homogenous multi-robot system, which is inspired by the task allocation practiced by social insects. We propose an extended probability model for proportion regulation, and confirm its performance by numerical simulation. We also experimentally validate its performance using a simple multi-robot system.

Pattern dynamics of directional crack propagation phenomena observed in drying process of starch-water mixture is investigated. To visualize the three-dimensional structure of the drying-fracture process two kinds of experiments are performed, i.e., resin solidification planing method and real-time measurement of water content distribution with MR instruments. A cross section with polygonal structure is visualized in both experiments. The depth dependency of cell size is measured. The phenomenological model for water transportation is also discussed.

The size frequency distribution of Japanese given names is analyzed. A power law behavior is observed in a small size range with an exponent smaller than 2, which is close to that of Japanese family names. A similar tendency is observed in the cases of names in other countries. A Galton–Watson-type model with a generalized Yule process combined with an Exclusion Principle in Family (EPiF) is suggested.

We isolated NSD1 from the 5q35 breakpoint in an individual with Sotos syndrome harboring a chromosomal translocation. We identified 1 nonsense, 3 frameshift and 20 submicroscopic deletion mutations of NSD1 among 42 individuals with sporadic cases of Sotos syndrome. The results indicate that haploinsufficiency of NSD1 is the major cause of Sotos syndrome.