Masamichi Takagi

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We propose a novel replacement algorithm, called Inter-Reference Gap Distribution Replacement (IGDR), for set-associative secondary caches of processors. IGDR attaches a weight to each memory-block, and on a replacement request it selects the memory-block with the smallest weight for eviction. The time difference between successive references of a(More)
The diversity and succession of microbial communities during the garbage composting with rice hull as an amendment were studied by denaturing gradient gel electrophoresis (DGGE) and clone library analysis of PCR-amplified 16S ribosomal DNA (rDNA) with universal primers. Based on temperature changes, the composting process could be divided into thermophilic,(More)
Two 3-phosphoglycerate kinase genes (pgk1 and pgk2) were cloned from Rhizopus niveus. It was deduced that both pgk genes have two introns. They have open reading frames of 1355 bp and 1356 bp, and code for proteins of 417 and 416 amino acids, respectively. The first introns of both genes are located at similar positions as those of pgk genes from other(More)
We have cloned a pyr4 gene encoding orotidine-5′-monophosphate decarboxylase of the filamentous fungus Rhizopus niveus. The pyr4 gene of R. nivens has an open reading frame composed of 265 amino-acid residues and has two putative introns. We have also isolated a pyr4 mutant of Rhizopus delemar from 5-fluoroorotic acid-resistant mutants and transformed it(More)
The functions of two previously identified chitin synthase genes in Aspergillus nidulans, chsB and chsD, were analysed. First, a conditional chsB mutant was constructed in which the expression of chsB is under the control of a repressible promoter, the alcA promoter, of A. nidulans. Under repressing conditions, the mutant grew slowly and produced highly(More)
tRNA 3' processing endoribonuclease (3' tRNase) is an enzyme responsible for the removal of a 3' trailer from precursor tRNA (pre-tRNA). We purified approximately 85 kDa 3' tRNase from pig liver and determined its partial sequences. BLAST search of them suggested that the enzyme was the product of a candidate human prostate cancer susceptibility gene,(More)
DCFA-MPI is an MPI library implementation for Intel Xeon Phi co-processor clusters, where a compute node consists of an Intel Xeon Phi co-processor card connected to the host via PCI Express with InfiniBand. DCFA-MPI enables direct data transfer between Intel Xeon Phi co-processors without assistance from the host. Since DCFA, a direct communication(More)
tRNase Z, which exists in almost all cells, is believed to be working primarily for tRNA 3' maturation. In Escherichia coli, however, the tRNase Z gene appears to be dispensable under normal growth conditions, and its physiological role is not clear. Here, to investigate a possibility that E. coli tRNase Z cleaves RNAs other than pre-tRNAs, we tested(More)
As systems sizes increase to exascale and beyond, there is a need to enhance the system software to meet the needs and challenges of applications. The evolutionary versus revolutionary debate can be set aside by providing system software that simultaneously supports existing and new programming models. The seemingly contradictory requirements of scalable(More)
A Gram-positive poly(3-hydroxybutyrate) (PHB)-degrading bacterial strain was isolated from compost. This organism, identified as Bacillus megaterium N-18-25-9, produced a clearing zone on opaque NB-PHB agar, indicating the presence of extracellular PHB depolymerase. A PHB depolymerase gene, PhaZ(Bm), of B. megaterium N-18-25-9 was cloned and sequenced, and(More)