Compiler-assisted multiple instruction rollback recovery using a read buffer

Multiple instruction rollback (MIR) is a technique that has been implemented in mainframe computers to provide rapid recovery from transient processor failures. Hardware-based MIR designs eliminate rollback data hazards by providing data redundancy implemented in hardware. Compiler-based MIR designs have also been developed which remove rollback data hazards directly with data-flow transformations. This paper describes compiler-assisted techniques to achieve multiple instruction rollback recovery. We observe that some data hazards resulting from instruction rollback can be resolved efficiently by providing an operand read buffer while others are resolved more efficiently with compiler transformations. The compiler-assisted scheme presented consists of hardware that is less complex than shadow files, history files, history buffers, or delayed write buffers, while experimental evaluation indicates performance improvement over compiler-based schemes

Formation and genotoxicity of a guanine–cytosine intrastrand cross-link lesion in vivo

Reactive oxygen species (ROS) can be induced by both endogenous and exogenous processes, and they can damage biological molecules including nucleic acids. Exposure of isolated DNA to X/γ-rays and Fenton reagents was shown to lead to the formation of intrastrand cross-link lesions where the neighboring nucleobases in the same DNA strand are covalently bonded. By employing HPLC coupled with tandem mass spectrometry (LC-MS/MS) with the isotope dilution method, we assessed quantitatively the formation of a guanine–cytosine (G[8-5]C) intrastrand cross-link lesion in HeLa-S3 cells upon exposure to γ-rays. The yield of the G[8-5]C cross-link was 0.037 lesions per 109 nucleosides per Gy, which was ∼300 times lower than that of 5-formyl-2′-deoxyuridine (0.011 lesions per 106 nucleosides per Gy) under identical exposure conditions. We further constructed a single-stranded M13 genome harboring a site-specifically incorporated G[8-5]C lesion and developed a novel mass spectrometry-based method for interrogating the products emanating from the replication of the genome in Escherichia coli cells. The results demonstrated that G[8-5]C blocked considerably DNA replication as represented by a 20% bypass efficiency, and the lesion was significantly mutagenic in vivo, which included a 8.7% G→T and a 1.2% G→C transversion mutations. DNA replication in E. coli hosts deficient in SOS-induced polymerases revealed that polymerase V was responsible for the error-prone translesion synthesis in vivo

Ranking of Interval-Valued Fuzzy Sets Based on Signed Distance

In this article, we use the signed distance to consider the ranking problem of interval- valued fuzzy sets. This ranking can be used in decision-making problem based on interval-valued fuzzy sets, or in the fuzzi¯cation or defuzzi¯cation of two sides of an equation in the fuzzy sense. We can learn that how far it is between two interval- valued fuzzy sets by the ranking of the signed distance

Convergency of the Fuzzy Vectors in the Pseudo Fuzzy Vector space over F^1_p(1)

In ﹝4﹞,we consider the pseudo fuzzy vector space SFR over F^1_p(1).Here we further discuss the convergency of the fuzzy vectors in SF