86 research outputs found

    DEC1 negatively regulates AMPK activity via LKB1

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    Basic helix-loop-helix (bHLH) transcription factor DEC1 (bHLHE40/Stra13/Sharp2) is one of the clock genes that show a circadian rhythm in various tissues. AMP-activated protein kinase (AMPK) activity plays important roles in the metabolic process and in cell death induced by glucose depletion. Recent reports have shown that AMPK activity exhibited a circadian rhythm. However, little is known regarding the regulatory mechanisms involved in the circadian rhythm of AMPK activity. The aim of this study is to investigate whether there is a direct correlation between DEC1 expression and AMPK activity. DEC1 protein and AMPK activity showed a circadian rhythm in the mouse liver with different peak levels. Knocking down DEC1 expression increased AMPK activity, whereas overexpression of DEC1 decreased it. Overexpressing the DEC1 basic mutants had little effect on the AMPK activity. DEC1 bound to the E-box of the LKB1 promoter, decreased LKB1 activity and total protein levels. There was an inverse relationship between DEC1 expression and AMPK activity. Our results suggest that DEC1 negatively regulates AMPK activity via LKB1

    Properties and evolution of emission in molecular aggregates of a perylene ammonium derivative in polymer matrices

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    Accepted 27 Jul 2015Size-dependent fluorescent properties of aggregates of a perylene ammonium derivative (PeryAm) were studied by steady-state and time-resolved spectroscopic methods. Quantitative analyses of aggregated states in aqueous solution indicated that the aggregation proceeded through dimer units of PeryAm. The fluorescence of the aggregate in the PVA film prepared from the aqueous solution continuously redshifted with an increase in the concentration of PeryAm in the mother liquor while keeping the absorption spectra in almost the same band shapes. Fluorescence anisotropy values of aggregates in the PVA film were dependent on the monitoring wavelength, and time profiles of the fluorescence at longer wavelengths showed a rapid increase just after the pulsed excitation. These results indicated efficient energy transfer to the stable sites in aggregates. Fluorescence microscopy images showed that aggregates were segregated in the PVA film and the color of the emission was dependent on the size of the aggregate. Under the steady-state irradiation, the emission color of the aggregates changed from green to yellow, which was attributable to the association of a small cluster of PeryAm with the green emission resulting in the formation of yellow-colored aggregates. On the basis of these results, we have discussed the mechanisms and dynamics of the aggregation and size-dependent emission in aggregates.ArticlePHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES. 14(10):1896-1902 (2015)journal articl

    Book Recommendation Based on Library Loan Records and Bibliographic Information

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    AbstractIn order to show the effectiveness of using (a) library loan records and (b) information about book contents as a basis for book recommendations, we entered various data into a support vector machine (SVM), used it to recommend books to subjects, and asked them for evaluations of the recommendations that were given. The data that we used were (1) confidence and support with an association rule that was based on the loan records, (2) similarities between book titles, (3) matches/mismatches between the Nippon Decimal Classification (NDC) categories of the books, and (4) similarities between the outlines of the books in the BOOK Database. The subjects were 32 students who belonged to T University. The books that we recommended and the loan records that we used were obtained from the T University Library. The results showed that the combinations of (1), (2), (3) and (1), (2) were rated more favorably by the subjects than the other combinations. However, the books that were recommended by Amazon were rated even more favorably by the subjects. This is a topic for further research

    Atomic force microscopy sees nucleosome positioning and histone H1-induced compaction in reconstituted chromatin

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    AbstractWe addressed the question of how nuclear histones and DNA interact and form a nucleosome structure by applying atomic force microscopy to an in vitro reconstituted chromatin system. The molecular images obtained by atomic force microscopy demonstrated that oligonucleosomes reconstituted with purified core histones and DNA yielded a ‘beads on a string’ structure with each nucleosome trapping 158±27 bp DNA. When dinucleosomes were assembled on a DNA fragment containing two tandem repeats of the positioning sequence of the Xenopus 5S RNA gene, two nucleosomes were located around each positioning sequence. The spacing of the nucleosomes fluctuated in the absence of salt and the nucleosomes were stabilized around the range of the positioning signals in the presence of 50 mM NaCl. An addition of histone H1 to the system resulted in a tight compaction of the dinucleosomal structure

    Yearly variations in Be-7 concentrations in surface air at Iceland and Japan  for 15 years from 2003: Solar modulation of cosmogenic nuclide

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    The Tenth Symposium on Polar Science/Ordinary sessions: [OS] Space and upper atmospheric sciences, Wed. 4 Dec. / Institute of Statistics and Mathematics (ISM) Seminar room 2 (D304) (3rd floor
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