Status Report of Neutral Kaon photo-production study using Neutral Kaon Spectrometer 2 (NKS2) at LNS-Tohoku(I. Nuclear Physics)

The approach described in this paper uses an array of Field Programmable Gate Array (FPGA) devices to implement a fault tolerant hardware system that can be compared to the running of fault tolerant software on a traditional processor. Fault tolerance is achieved is achieved by using FPGA with on the fly partial programmability feature. Major considerations while mapping to the FPGA includes the size of the area to be mapped and communication issues related to their communication. Area size selection is compared to the page size selection in Operating System Design. Communication issues between modules are compared to the software engineering paradigms dealing with module coupling, fan-in, fan-out and cohesiveness. Finally, the overhead associated with the downloading of the reconfiguration files is discussed

CRISPR Inhibition of Prophage Acquisition in Streptococcus pyogenes

Streptococcus pyogenes, one of the major human pathogens, is a unique species since it has acquired diverse strain-specific virulence properties mainly through the acquisition of streptococcal prophages. In addition, S. pyogenes possesses clustered regularly interspaced short palindromic repeats (CRISPR)/Cas systems that can restrict horizontal gene transfer (HGT) including phage insertion. Therefore, it was of interest to examine the relationship between CRISPR and acquisition of prophages in S. pyogenes. Although two distinct CRISPR loci were found in S. pyogenes, some strains lacked CRISPR and these strains possess significantly more prophages than CRISPR harboring strains. We also found that the number of spacers of S. pyogenes CRISPR was less than for other streptococci. The demonstrated spacer contents, however, suggested that the CRISPR appear to limit phage insertions. In addition, we found a significant inverse correlation between the number of spacers and prophages in S. pyogenes. It was therefore suggested that S. pyogenes CRISPR have permitted phage insertion by lacking its own spacers. Interestingly, in two closely related S. pyogenes strains (SSI-1 and MGAS315), CRISPR activity appeared to be impaired following the insertion of phage genomes into the repeat sequences. Detailed analysis of this prophage insertion site suggested that MGAS315 is the ancestral strain of SSI-1. As a result of analysis of 35 additional streptococcal genomes, it was suggested that the influences of the CRISPR on the phage insertion vary among species even within the same genus. Our results suggested that limitations in CRISPR content could explain the characteristic acquisition of prophages and might contribute to strain-specific pathogenesis in S. pyogenes

Mechanism of <i>S</i>‑Adenosyl‑l‑methionine <i>C</i>‑Methylation by Cobalamin-dependent Radical <i>S</i>‑Adenosyl‑l‑methionine Methylase in 1‑Amino-2-methylcyclopropanecarboxylic Acid Biosynthesis

The radical S-adenosyl-l-methionine (SAM) methylase Orf29 catalyzes the C-methylation of SAM in the biosynthesis of 1-amino-2-methylcyclopropanecarboxylic acid. Here, we determined that the methylation product is (4″R)-4″-methyl-SAM. Furthermore, we found that the 5′-deoxyadenosyl radical generated by Orf29 abstracts the pro-R hydrogen atom from the C-4″ position of SAM to generate the radical intermediate, which reacts with methylcobalamin to give (4″R)-4″-methyl-SAM. Consequently, the Orf29-catalyzed C-methylation was confirmed to proceed with retention of configuration