KamLAND-Zenでのニュートリノを伴わない二重ベータ崩壊測定によるニュートリノのマヨラナ質量への制限

Tohoku University井上邦雄課

Multi-layered flyer accelerated by laser induced shock waves

Copyright 2000 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 7(2), 676-680, 2000 and may be found at http://dx.doi.org/10.1063/1.87385

Osteoclasts are dispensable for hematopoietic stem cell maintenance and mobilization

The mobilization of hematopoietic stem cells does not require osteoclasts, which may even have an inhibitory effect

Identification of mTEC precursor cells

Medullary thymic epithelial cells (mTECs) expressing autoimmune regulator (Aire) are critical for preventing the onset of autoimmunity. However, the differentiation program of Aire-expressing mTECs (Aire+ mTECs) is unclear. Here, we describe novel embryonic precursors of Aire+ mTECs. We found the candidate precursors of Aire+ mTECs (pMECs) by monitoring the expression of receptor activator of nuclear factor-κB (RANK), which is required for Aire+ mTEC differentiation. pMECs unexpectedly expressed cortical TEC molecules in addition to the mTEC markers UEA-1 ligand and RANK and differentiated into mTECs in reaggregation thymic organ culture. Introduction of pMECs in the embryonic thymus permitted long-term maintenance of Aire+ mTECs and efficiently suppressed the onset of autoimmunity induced by Aire+ mTEC deficiency. Mechanistically, pMECs differentiated into Aire+ mTECs by tumor necrosis factor receptor-associated factor 6-dependent RANK signaling. Moreover, nonclassical nuclear factor-κB activation triggered by RANK and lymphotoxin-β receptor signaling promoted pMEC induction from progenitors exhibiting lower RANK expression and higher CD24 expression. Thus, our findings identified two novel stages in the differentiation program of Aire+ mTECs

Development of a Cylindrical Drift Chamber for the COMET Phase-I Experiment

International audienceA search for $\mu$–e conversion, the COMET experiment, will be conducted at J-PARC. The experiment has two phases. Phase-I aims to measure the background directly and search for $\mu$–e conversion with a sensitivity of 10^−15. Phase-II will use the information gained in Phase-I and utilize a much more intense muon beam to achieve a sensitivity of 10^−17. The main detector of the COMET Phase-I experiment is a cylindrical drift chamber (CDC). The COMET CDC will be installed in a solenoidal magnetic field, surrounding the muon stopping targets. It was designed to efficiently detect signal electrons of $\mu$–e conversion (105 MeV/c) emitted from the targets with momentum resolution of 200 keV/c. The COMET CDC has already been constructed and the performance test using cosmic ray is in progress. The details of the CDC design and the analysis results of the cosmic ray test is reported