Evaluation of field condition by using smart rice transplanter

Lodging of rice has become a big problem for large scale farmer during harvesting season. Investigating topsoil depth (TD) and apparent electrical conductivity (ECa) of paddy field will be the key to solve this problem. In this study, we developed smart rice transplanter, which could measure TD and ECa. The TD was measured by ultrasonic distance sensor (USS). The ECa was measured by soil electrical conductivity sensor (ECS). We defined that the ECa measured by ECS was soil fertility value (SFV). Each sensor could obtain data every one second. As a result of field test in 2016, total 740,000 of datasets were collected from 50ha paddy. The average of the TD was 19.8 cm while the maximum, minimum, and standard deviation (SD) of TD were 68.47, 7.45 and 6.62 cm respectively. The average of the SFV was 1.04 mS/cm while the maximum, minimum, and SD of SFV were 9.57, 0.07 and 0.68 mS/cm respectively. The result also revealed that high TD was observed in heading area due to machine turning inside the field. In this study, TD and SFV were also applied for variable rate fertilizer application. We designed variable rate ratio with 4 levels. Level 1 where high TD zone reduced by 30%. Level 2 where high SFV zone reduced by 20%. Level 3 where a little high SFV zone reduced by 10%. Level 4 where the other zone fertilized conventional amount. As a result, the smart rice transplanter saved 20% of fertilizer than conventional application

Split luciferase complementation assay to detect regulated protein-protein interactions in rice protoplasts in a large-scale format

© 2014 Fujikawa et al. Background: The rice interactome, in which a network of protein-protein interactions has been elucidated in rice, is a useful resource to identify functional modules of rice signal transduction pathways. Protein-protein interactions occur in cells in two ways, constitutive and regulative. While a yeast-based high-throughput method has been widely used to identify the constitutive interactions, a method to detect the regulated interactions is rarely developed for a large-scale analysis. Results: A split luciferase complementation assay was applied to detect the regulated interactions in rice. A transformation method of rice protoplasts in a 96-well plate was first established for a large-scale analysis. In addition, an antibody that specifically recognizes a carboxyl-terminal fragment of Renilla luciferase was newly developed. A pair of antibodies that recognize amino- and carboxyl- terminal fragments of Renilla luciferase, respectively, was then used to monitor quality and quantity of interacting recombinant-proteins accumulated in the cells. For a proof-of-concept, the method was applied to detect the gibberellin-dependent interaction between GIBBERELLIN INSENSITIVE DWARF1 and SLENDER RICE 1. Conclusions: A method to detect regulated protein-protein interactions was developed towards establishment of the rice interactome

Dynamical Properties of the 1/r^2-Type Supersymmetric t-J Model in a Magnetic Field: Manifestation of Spin-Charge Separation

Quasi-particle picture in a magnetic field is pursued for dynamical spin and charge correlation functions of the one-dimensional supersymmetric t-J model with inverse-square interaction. With use of exact diagonalization and the asymptotic Bethe-ansatz equations for finite systems, excitation contents of relevant excited states are identified which are valid in the thermodynamic limit. The excitation contents are composed of spinons, antispinons, holons and antiholons obeying fractional statistics. Both longitudinal and transverse components of the dynamical spin structure factor are independent of the electron density in the region where only quasi-particles with spin degrees of freedom (spinons and antispinons) contribute. The dynamical charge structure factor does not depend on the spin-polarization density in the region where only quasi-particles with charge (holons and antiholons) are excited. These features indicate the strong spin-charge separation in dynamics, reflecting the high symmetry of the model.Comment: 10 pages, 1 table (PS file), 15 figures (JPEG file). Submitted to J. Phys. Soc. Jp

Exact evaluation of density matrix elements for the Heisenberg chain

We have obtained all the density matrix elements on six lattice sites for the spin-1/2 Heisenberg chain via the algebraic method based on the quantum Knizhnik-Zamolodchikov equations. Several interesting correlation functions, such as chiral correlation functions, dimer-dimer correlation functions, etc... have been analytically evaluated. Furthermore we have calculated all the eigenvalues of the density matrix and analyze the eigenvalue-distribution. As a result the exact von Neumann entropy for the reduced density matrix on six lattice sites has been obtained.Comment: 33 pages, 4 eps figures, 3 author

Spin-Charge Separation at Finite Temperature in the Supersymmetric t-J Model with Long-Range Interactions

Thermodynamics is derived rigorously for the 1D supersymmetric {\it t-J} model and its SU($K,1$) generalization with inverse-square exchange. The system at low temperature is described in terms of spinons, antispinons, holons and antiholons obeying fractional statistics. They are all free and make the spin susceptibility independent of electron density, and the charge susceptibility independent of magnetization. Thermal spin excitations responsible for the entropy of the SU($K,1$) model are ascribed to free para-fermions of order $K-1$.Comment: 10 pages, REVTE

Spinless Calogero-Sutherland model with twisted boundary condition

In this work, the spinless Calogero-Sutherland model with twisted boundary condition is studied. The ground state wavefunctions, the ground state energies, the full energy spectrum are provided in details.Comment: preprint of ETH-L, appearing in recent PR

Alternating spin chains with singlet ground states

We investigate low-energy properties of the alternating spin chain model composed of spin $s_1$ and $s_2$ with a singlet ground state. After examining the spin-wave spectrum in detail, we map low-energy spin excitations to the O(3) non-linear sigma model in order to take into account quantum fluctuations. Analyzing the topological term in the resulting sigma model, we discuss how the massless or massive excitations are developed, especially according to the topological nature of the alternating spin system.Comment: 9 pages, revtex, to appear in PR

Elementary Excitations and Dynamical Correlation Functions of the Calogero-Sutherland Model with Internal Symmetry

We consider the physical properties of elementary excitations of the Calogero-Sutherland (CS) model with SU(K) internal symmetry. From the results on the thermodynamics of this model, we obtain the charge, spin, and statistics of elementary excitations. Combining this knowledge and the known results on the dynamics in the spinless CS model, we propose the expression for the dynamical correlation functions of the SU(K) CS model. In the asymptotic region, we confirm the consistency of our results with predictions from conformal field theory.Comment: 22 pages, REVTe