654 research outputs found
Scattering and inverse scattering for nonlinear quantum walks
We study large time behavior of quantum walks (QWs) with self-dependent
(nonlinear) coin. In particular, we show scattering and derive the reproducing
formula for inverse scattering in the weak nonlinear regime. The proof is based
on space-time estimate of (linear) QWs such as dispersive estimates and
Strichartz estimate. Such argument is standard in the study of nonlinear
Schr\"odinger equations and discrete nonlinear Schr\"odinger equations but it
seems to be the first time to be applied to QW.Comment: 18 pages, text overlap with arXiv:1711.0062
A Language Support for Exhaustive Fault-Injection in Message-Passing System Models
This paper presents an approach towards specifying and verifying adaptive
distributed systems. We here take fault-handling as an example of adaptive
behavior and propose a modeling language Sandal for describing fault-prone
message-passing systems. One of the unique mechanisms of the language is a
linguistic support for abstracting typical faults such as unexpected
termination of processes and random loss of messages. The Sandal compiler
translates a model into a set of NuSMV modules. During the compilation process,
faults specified in the model will be woven into the output. One can thus enjoy
full-automatic exhaustive fault-injection without writing faulty behaviors
explicitly. We demonstrate the advantage of the language by verifying a model
of the two-phase commit protocol under faulty environment.Comment: In Proceedings MOD* 2014, arXiv:1411.345
pXBP1(U) encoded in XBP1 pre-mRNA negatively regulates unfolded protein response activator pXBP1(S) in mammalian ER stress response
Upon the accumulation of unfolded proteins in the mammalian endoplasmic reticulum (ER), X-box binding protein 1 (XBP1) premessenger RNA (premRNA) is converted to mature mRNA by unconventional splicing that is mediated by the endonuclease inositol-requiring enzyme 1. The transcription factor protein (p) XBP1 spliced (S), which is translated from mature XBP1 mRNA, contains the nuclear localization signal and the transcriptional activation domain and activates the transcription of target genes, including those encoding ER chaperones in the nucleus. We show that pXBP1 unspliced (U) encoded in XBP1 pre-mRNA was constitutively expressed and markedly accumulated at the recovery phase of ER stress. pXBP1(U) contained the nuclear exclusion signal instead of the transcriptional activation domain and shuttled between the nucleus and the cytoplasm. Interestingly, pXBP1(U) formed a complex with pXBP1(S), and the pXBP1(U)–pXBP1(S) complex was sequestered from the nucleus. Moreover, the complex was rapidly degraded by proteasomes because of the degradation motif contained in pXBP1(U). Thus, pXBP1(U) is a negative feedback regulator of pXBP1(S), which shuts off the transcription of target genes during the recovery phase of ER stress
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