Non-isospectral extension of the Volterra lattice hierarchy, and Hankel determinants

For the first two equations of the Volterra lattice hierarchy and the first two equations of its non-autonomous (non-isospectral) extension, we present Riccati systems for functions c_j(t), j=0,1,..., such that an expression in terms of Hankel determinants built from them solves these equations on the right half of the lattice. This actually achieves a complete linearization of these equations of the extended Volterra lattice hierarchy.Comment: 31 pages, 3rd version: introduction extended, part of Section 2 moved there, Appendix D added, additional references, to appear in Nonlinearit

Magnetized Accretion Disks with Outflows for Changing-look AGNs

Changing-look active galactic nuclei (CL-AGNs) challenges the standard accretion theory owing to its rapid variability. Recent numerical simulations have shown that, for the sub-Eddington accretion case, the disk is magnetic pressure-dominated, thermally stable, and geometrically thicker than the standard disk. In addition, outflows were found in the simulations. Observationally, high blueshifted velocities absorption lines indicate that outflows exist in AGNs. In this work, based on the simulation results, we investigate the magnetic pressure-dominated disk, and find that the accretion timescale is significantly shorter than that of the standard thin disk. However, such a timescale is still longer than that of the CL-AGNs. Moreover, if the role of outflows is taken into account, then the accretion timescale can be even shortened. By the detailed comparison of the theoretical accretion timescale with the observations, we propose that the magnetic pressure-dominated disk incorporating outflows can be responsible for the rapid variability of CL-AGNs.Comment: 11 pages, 3 figures, accepted for publication in Ap

Key-point Detection based Fast CU Decision for HEVC Intra Encoding

As the most recent video coding standard, High Efficiency Video Coding (HEVC) adopts various novel techniques, including a quad-tree based coding unit (CU) structure and additional angular modes used for intra encoding. These newtechniques achieve a notable improvement in coding efficiency at the penalty of significant computational complexity increase. Thus, a fast HEVC coding algorithm is highly desirable. In this paper, we propose a fast intra CU decision algorithm for HEVC to reduce the coding complexity, mainly based on a key-point detection. A CU block is considered to have multiple gradients and is early split if corner points are detected inside the block. On the other hand, a CU block without corner points is treated to be terminated when its RD cost is also small according to statistics of the previous frames. The proposed fast algorithm achieves over 62% encoding time reduction with 3.66%, 2.82%, and 2.53% BD-Rate loss for Y, U, and V components, averagely. The experimental results show that the proposed method is efficient to fast decide CU size in HEVC intra coding, even though only static parameters are applied to all test sequences

A diagnostic challenge for schistosomiasis japonica in China: consequences on praziquantel-based morbidity control

Worldwide schistosomiasis continues to be a serious public health problem. Over the past five decades, China has made remarkable progress in reducing Schistosoma japonicum infections in humans to a relatively low level. Endemic regions are currently circumscribed in certain core areas where re-infection and repeated chemotherapy are frequent. At present, selective chemotherapy with praziquantel is one of the main strategies in China's National Schistosomiasis Control Program, and thus diagnosis of infected individuals is a key step for such control. In this paper we review the current status of our knowledge about diagnostic tools for schistosomiasis japonica. A simple, affordable, sensitive, and specific assay for field diagnosis of schistosomiasis japonica is not yet available, and this poses great barriers towards full control of schistosomiasis. Hence, a search for a diagnostic approach, which delivers these characteristics, is essential and should be given high priority

Cellular Basis of Potato Spindle Tuber Viroid Systemic Movement

AbstractViroids are small, nontranslatable pathogenic RNAs that replicate autonomously and traffic systemically in their host plants. We have used in situ hybridization to analyze the trafficking pattern of Potato spindle tuber viroid (PSTVd) in tomato and Nicotiana benthamiana. When PSTVd was inoculated onto the stem of a plant, it replicated and trafficked to sink, but not source, leaves. PSTVd was absent from shoot apical meristems. In the flowers of infected plants, PSTVd was present in the sepals, but was absent in the petals, stamens, and ovary. The replicative form of PSTVd was detected in the phloem. Our data demonstrate that (i) PSTVd traffics long distance in the phloem and this trafficking is likely sustained by replication of the viroid in the phloem, and (ii) PSTVd trafficking is governed by plant developmental and cellular factors. The dependency of PSTVd and other viroids on cellular mechanisms for RNA trafficking makes them excellent tools to study such mechanisms