283 research outputs found
A fundamental study assessing the generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC) using the appendicitis detection task of computed tomography
Purpose: Increased use of deep learning (DL) in medical imaging diagnoses has led to more frequent use of 10-fold cross-validation (10-CV) for the evaluation of the performance of DL. To eliminate some of the (10-fold) repetitive processing in 10-CV, we proposed a "generalized fitting method in conjunction with every possible coalition of N-combinations (G-EPOC)", to estimate the range of the mean accuracy of 10-CV using less than 10 results of 10-CV. Material and methods: G-EPOC was executed as follows. We first provided (2N-1) coalition subsets using a specified N, which was 9 or less, out of 10 result datasets of 10-CV. We then obtained the estimation range of the accuracy by applying those subsets to the distribution fitting twice using a combination of normal, binominal, or Poisson distributions. Using datasets of 10-CVs acquired from the practical detection task of the appendicitis on CT by DL, we scored the estimation success rates if the range provided by G-EPOC included the true accuracy. Results: G-EPOC successfully estimated the range of the mean accuracy by 10-CV at over 95% rates for datasets with N assigned as 2 to 9. Conclusions: G-EPOC will help lessen the consumption of time and computer resources in the development of computer-based diagnoses in medical imaging and could become an option for the selection of a reasonable K value in K-CV
A third glucose uptake bypass in Corynebacterium glutamicum ATCC 31833
In Corynebacterium glutamicum, the phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS) has long been the only known glucose uptake system, but we recently found suppressor mutants emerging from a PTS-negative strain of C. glutamicum ATCC 31833 on glucose agar plates, and identified two alternative potential glucose uptake systems, the myo-inositol transporters encoded by iolT1 and iolT2. The expression of either gene renders the PTS-negative strain WT Delta ptsH capable of growing on glucose. In the present study, we found a suppressor strain that still grew on glucose even after the iolT1 and iolT2 genes were both disrupted under the PTS-negative background. Whole-genome sequencing of the suppressor strain SPH1 identified a G-to-T exchange at 134 bp upstream of the bglF gene encoding an EII component of the beta-glucoside-PTS, which is found in limited wild-type strains of C. glutamicum. Introduction of the mutation into strain WT Delta ptsH allowed the PTS-negative strain to grow on glucose. Reverse transcription-quantitative PCR analysis revealed that the mutation upregulates the bglF gene by approximately 11-fold. Overexpression of bglF under the gapA promoter in strain WT Delta ptsH rendered the strain capable of growing on glucose, and deletion of bglF in strain SPH1 abolished the growth again, proving that bglF is responsible for glucose uptake in the suppressor strain. Simultaneous disruption of three glucokinase genes, glk (Cgl2185, NCgl2105), ppgK (Cgl1910, NCgl1835), and Cgl2647 (NCgl2558), in strain SPH1 resulted in no growth on glucose. Plasmid-mediated expression of any of the three genes in the triple-knockout mutant restored the growth on glucose. These results indicate that C. glutamicum ATCC 31833 has an additional non-PTS glucose uptake route consisting of the bglF-specified EII permease and native glucokinases.ArticleAPPLIED MICROBIOLOGY AND BIOTECHNOLOGY. 99(6):2741-2750 (2015)journal articl
<Regular Article>Evaluation of Self-Association Energies of 2-Pyridone Tautomers by Modified MNDO Methods
We have carried out the molecular orbital calculations supported by the modified MNDO methods (MNDO/H, Modified MNDO and Am1) to study the self-associations of formic acid, 2-pyridone and its tautomer, 2-pyridinol. The greater self-association energy of 2-pyridone than that of 2-pyridinol was shown in all the methods. The calculated self-association energies of formic acid and 2-pyridone by the MNDO/H method were well compatible with the experimental values. However, the difference in energy between two tautomers of 2-pyridone was too small to reproduce the experimentally known values. On the other hand, it was found that the Modified MNDO method was invalid for the doubly hydrogen-bonded systems. The AM1 method have been shown to give a proper account of the tautomeric features of 2-pyridone, although the calculated energies of hydrogen-bonding were only about a half the experimental values
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