2-(Furan-2-yl)-5-(2-nitro­benz­yl)-2,3-dihydro-1,5-benzothia­zepin-4(5H)-one

The title compound, C20H16N2O4S, was prepared by introduction of a 2-nitro­benzyl group to 2-(furan-2-yl)-2,3-dihydro-1,5-benzothia­zepin-4(5H)-one via an alkaline-catalysed reaction. The thia­zepine ring adopts a twist-boat conformation. The furan ring is oriented at dihedral angles of 56.75 (14) and 10.82 (14)° with respect to the two benzene rings, while the two benzene rings make a dihedral angle of 62.96 (10)°. Weak inter­molecular C—H⋯O hydrogen bonds occur in the crystal structure

Light-cone Sum Rule Analysis of Semileptonic Decays Λb0→Λc+ℓ−ν‾ℓ\Lambda_b^0 \to \Lambda_c^+ \ell^- \overline{\nu}_\ell

In this work, we analyze the semileptonic decay processes of $\Lambda_b \to \Lambda_c$ in the light-cone sum rule approach. In the calculation of the form factors of $\Lambda_b$ baryon transition matrix element, the light-cone distribution amplitudes of $\Lambda_b$ which are obtained from QCD sum rule in the heavy quark effective field theory framework are used. With the calculation of the six form factors of $\Lambda_b \to \Lambda_c$ transition matrix element, the differential decay widths of $\Lambda_b^0 \to \Lambda_c^+ \ell^- \overline{\nu}_\ell (\ell = e, \mu, \tau)$ and absolute branching fractions are obtained. Additionally the ratio of $R(\Lambda_c)=\mathcal{B}r(\Lambda_b\to \Lambda_c e \nu_e)/\mathcal{B}r(\Lambda_b \to \Lambda_c \tau \nu_\tau)$ is obtained. These results are in accordance with the newest experimental result and other theoretical calculations and predictions.Comment: 10 pages,6 figure

Bayesian System Identification based on Hierarchical Sparse Bayesian Learning and Gibbs Sampling with Application to Structural Damage Assessment

The focus in this paper is Bayesian system identification based on noisy incomplete modal data where we can impose spatially-sparse stiffness changes when updating a structural model. To this end, based on a similar hierarchical sparse Bayesian learning model from our previous work, we propose two Gibbs sampling algorithms. The algorithms differ in their strategies to deal with the posterior uncertainty of the equation-error precision parameter, but both sample from the conditional posterior probability density functions (PDFs) for the structural stiffness parameters and system modal parameters. The effective dimension for the Gibbs sampling is low because iterative sampling is done from only three conditional posterior PDFs that correspond to three parameter groups, along with sampling of the equation-error precision parameter from another conditional posterior PDF in one of the algorithms where it is not integrated out as a "nuisance" parameter. A nice feature from a computational perspective is that it is not necessary to solve a nonlinear eigenvalue problem of a structural model. The effectiveness and robustness of the proposed algorithms are illustrated by applying them to the IASE-ASCE Phase II simulated and experimental benchmark studies. The goal is to use incomplete modal data identified before and after possible damage to detect and assess spatially-sparse stiffness reductions induced by any damage. Our past and current focus on meeting challenges arising from Bayesian inference of structural stiffness serve to strengthen the capability of vibration-based structural system identification but our methods also have much broader applicability for inverse problems in science and technology where system matrices are to be inferred from noisy partial information about their eigenquantities.Comment: 12 figure

Establishment of persistent infection with foot-and-mouth disease virus in BHK-21 cells

<p>Abstract</p> <p>Background</p> <p>Foot-and-mouth disease virus (FMDV) is able to cause persistent infection in ruminants besides acute infection and disease. Since the mechanisms of viral persistence and the determining factors are still unknown, <it>in vitro </it>systems help explore and reveal mechanisms of persistence <it>in vivo </it>by providing useful models for the study of RNA genome mutations and evolution. Ammonium chloride, a lysosomotropic agent that raises intralysosomal pH, reduces the yield of FMDV during infection of BHK-21 cells.</p> <p>Results</p> <p>The persistent infection with FMDV serotype O in BHK-21 cells was selected and established readily after treatment of ammonium chloride that acts primarily on the cells. Intact virions were observed located inside the endosomes. Viral genome RNAs and specific proteins were detected in the persistent cells to validate the establishment of viral persistence. Infection of the persistent viruses could not form plaques in host cells but virulence was enhanced. Basing on analysis and comparison of cDNA sequences of resident viruses and wild type viruses, 15 amine acid mutations were found, all of which were located in nonstructural proteins rather than in structural proteins.</p> <p>Conclusions</p> <p>Therefore, persistent infection of cell cultures with FMDV is successfully established with some distinctive features. It would be worthwhile to further investigate the mechanisms of viral persistence.</p

Radio Polarization of BL Lacertae objects

In this paper, using the database of the university of Michigan Radio Astronomy Observatory (UMRAO) at three (4.8 GHz, 8 GHZ, and 14.5 GHz) radio frequencies, we studied the polarization properties for 47 BL Lacertae objects(38 radio selected BL Lacertae objects, 7 X-ray selected BL Lacertae, and two inter-middle objects (Mkn 421 and Mkn 501), and found that (1) The polarizations at higher radio frequency is higher than those at lower frequency, (2) The variability of polarization at higher radio frequency is higher than those at lower frequency, (3) The polarization is correlated with the radio spectral index, and (4) The polarization is correlated with core-dominance parameter for those objects with known core-dominance parameters suggesting that the relativistic beaming could explain the polarization characteristic of BL Lacs.Comment: 5 pages, 3 figures, 1 table. PASJ, in pres

MicroRNA-23a promotes myelination in the central nervous system.

Demyelinating disorders including leukodystrophies are devastating conditions that are still in need of better understanding, and both oligodendrocyte differentiation and myelin synthesis pathways are potential avenues for developing treatment. Overexpression of lamin B1 leads to leukodystrophy characterized by demyelination of the central nervous system, and microRNA-23 (miR-23) was found to suppress lamin B1 and enhance oligodendrocyte differentiation in vitro. Here, we demonstrated that miR-23a-overexpressing mice have increased myelin thickness, providing in vivo evidence that miR-23a enhances both oligodendrocyte differentiation and myelin synthesis. Using this mouse model, we explored possible miR-23a targets and revealed that the phosphatase and tensin homologue/phosphatidylinositol trisphosphate kinase/Akt/mammalian target of rapamycin pathway is modulated by miR-23a. Additionally, a long noncoding RNA, 2700046G09Rik, was identified as a miR-23a target and modulates phosphatase and tensin homologue itself in a miR-23a-dependent manner. The data presented here imply a unique role for miR-23a in the coordination of proteins and noncoding RNAs in generating and maintaining healthy myelin