49 research outputs found
Reconstruction of quark mass matrices in the NNI form from the experimental data
We examined the question that what is a general form of quark mass matrices
which is achieved by the transformation that leaves the left-handed gauge
interaction invariant. In particular, we analyzed in detail the Fritzsch-type
and the Branco-Silva-Marcos-type parametrization. Both parametrizations contain
ten parameters and can be expressed by the experimental data. We explicitly
reconstructed quark mass matrices in terms of quark masses and CKM parameters
for the Fritzsch-type parametrization.Comment: 17 pages and 4 figure
Quantum effects for the neutrino mixing matrix in the democratic-type model
We investigate the quantum effects for the democratic-type neutrino mass
matrix given at the right-handed neutrino mass scale in order to see (i)
whether predicted by the model is stable to explain the
atmospheric neutrino anomaly, (ii) how and behave,
and (iii) whether the predicted Dirac CP phase keeps maximal size, at
the weak scale . We find that, for the (inversely) hierarchical mass
spectrum with , and are stable, while
is not so, which leads to the possibility that the solar neutrino
mixing angle can become large at even if it is taken small at . We
also show that keeps almost maximal for the above mass spectrum, and
our model can give the large CP violation effect in the future neutrino
oscillation experiments if the solar neutrino puzzle is explained by the large
mixing angle MSW solution.Comment: LaTeX, 21 pages, 2 figures, some mistakes correcte
DNA methylation status of nuclear-encoded mitochondrial genes underlies the tissue-dependent mitochondrial functions
<p>Abstract</p> <p>Background</p> <p>Mitochondria are semi-autonomous, semi-self-replicating organelles harboring their own DNA (mitochondrial DNA, mtDNA), and their dysregulation is involved in the development of various diseases. While mtDNA does not generally undergo epigenetic modifications, almost all mitochondrial proteins are encoded by nuclear DNA. However, the epigenetic regulation of nuclear-encoded mitochondrial genes (nuclear mt genes) has not been comprehensively analyzed.</p> <p>Results</p> <p>We analyzed the DNA methylation status of 899 nuclear mt genes in the liver, brain, and heart tissues of mouse, and identified 636 nuclear mt genes carrying tissue-dependent and differentially methylated regions (T-DMRs). These nuclar mt genes are involved in various mitochondrial functions and they also include genes related to human diseases. T-DMRs regulate the expression of nuclear mt genes. Nuclear mt genes with tissue-specific hypomethylated T-DMRs were characterized by enrichment of the target genes of specific transcription factors such as FOXA2 in the liver, and CEBPA and STAT1 in the brain.</p> <p>Conclusions</p> <p>A substantial proportion of nuclear mt genes contained T-DMRs, and the DNA methylation status of numerous T-DMRs should underlie tissue-dependent mitochondrial functions.</p
Unified Explanation of Quark and Lepton Masses and Mixings in the Supersymmetric SO(10) Model
We discussed neutrino masses and mixings in SUSY SO(10) model where quarks
and leptons have Yukawa couplings to at least two 10 and one Higgs
scalars. In this model, the Dirac and the right-handed Majorana mass terms are
expressed by linear combinations of quark and charged lepton mass matrices,
which then determine the neutrino mass matrix by the see-saw mechanism. We show
that there are various solutions to reproduce a large mixing angle for
and a small mixing angle for , as well as the
hierarchical mass spectrum of neutrinos.Comment: LaTeX, 32 pages including 15 eps figure
ACPA-negative RA consists of two genetically distinct subsets based on RF positivity in Japanese.
HLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA). However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated peptide/protein antibody (ACPA). We have recently reported that ACPA-negative RA is associated with specific HLA-DRB1 alleles and diplotypes. Here, we attempted to detect genetically different subsets of ACPA-negative RA by classifying ACPA-negative RA patients into two groups based on their positivity for rheumatoid factor (RF). HLA-DRB1 genotyping data for totally 954 ACPA-negative RA patients and 2,008 healthy individuals in two independent sets were used. HLA-DRB1 allele and diplotype frequencies were compared among the ACPA-negative RF-positive RA patients, ACPA-negative RF-negative RA patients, and controls in each set. Combined results were also analyzed. A similar analysis was performed in 685 ACPA-positive RA patients classified according to their RF positivity. As a result, HLA-DRB1*04:05 and *09:01 showed strong associations with ACPA-negative RF-positive RA in the combined analysis (pâ=â8.8Ă10(-6) and 0.0011, OR: 1.57 (1.28-1.91) and 1.37 (1.13-1.65), respectively). We also found that HLA-DR14 and the HLA-DR8 homozygote were associated with ACPA-negative RF-negative RA (pâ=â0.00022 and 0.00013, OR: 1.52 (1.21-1.89) and 3.08 (1.68-5.64), respectively). These association tendencies were found in each set. On the contrary, we could not detect any significant differences between ACPA-positive RA subsets. As a conclusion, ACPA-negative RA includes two genetically distinct subsets according to RF positivity in Japan, which display different associations with HLA-DRB1. ACPA-negative RF-positive RA is strongly associated with HLA-DRB1*04:05 and *09:01. ACPA-negative RF-negative RA is associated with DR14 and the HLA-DR8 homozygote