92 research outputs found
The Role of Interferon Regulatory Factor-1 and Interferon Regulatory Factor-2 in IFN-γ Growth Inhibition of Human Breast Carcinoma Cell Lines
Interferon (IFN) regulatory factor-1 (IRF-1) and IRF-2 play opposing roles in the regulation of many IFN-γ-inducible genes. To investigate the signal transduction pathway in response to IFN-γ in light of differences in growth effects, we selected four human breast carcinoma cell lines based on a spectrum of growth inhibition by IFN-γ. MDA468 growth was markedly inhibited by IFN-γ, and it showed substantial induction of IRF-1 mRNA but little IRF-2 induction. SKBR3 showed little growth inhibition and little induction of IRF-1 mRNA but significant induction of IRF-2 mRNA. HS578T and MDA436 growth inhibition and IRF-1/IRF-2 induction were intermediate. All four cell lines showed intact receptor at the cell surface and Stat1 translocation to the nucleus by immunostaining. By EMSA, there were marked differences in the induced ratio of IRF-1 and IRF-2 binding activity between the cell lines that correlated with growth inhibition. Finally, antisense oligonucleotides specific for IRF-1 attenuated IFN-γ growth inhibition in MDA436 and MDA468, confirming the direct role of IRF-1 in IFN-γ growth inhibition. Induction of IRF-1 causes growth inhibition in human breast cancer cell lines, and induction of IRF-2 can oppose this. The relative induction of IRF-1 to IRF-2 is a critical control point in IFN-γ response.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63111/1/10799900360708623.pd
Measurement of the decay width of He
We have precisely measured decay width of \5LHe and
demonstrated significantly larger - overlap than expected
from the central repulsion - potential, which is derived from
YNG \Lambda$-nucleon interaction.Comment: 4 pages, 3 figure
Proton asymmetry in non-mesonic weak decay of light hypernuclei
We have obtained the decay asymmetry parameters in non-mesonic weak decay of
polarized Lambda-hypernuclei by measuring the proton asymmetry. The polarized
Lambda-hypernuclei, 5_Lambda-He, 12_Lambda-C, and 11_Lambda-B, were produced in
high statistics via the (pi^+,k^+) reaction at 1.05 GeV/c in the forward
angles. Preliminary analysis shows that the decay asymmetry parameters are very
small for these s-shell and p-shell hypernuclei.Comment: 4pages, 4figures, International Conference on Hypernuclear and
Strange Particle Physics (HYP2003
pi^0 decay branching ratios of 5_Lambda-He and 12_Lambda-C hypernuclei
We precisely measured pi^0 branching ratios of 5_Lambda-He and 12_Lambda-C
hypernuclei produced via (pi^+,k^+) reaction. Using these pi^0 branching ratios
with the pi^- branching ratios and the lifetimes, we obtained the pi^0 decay
widths and the non-mesonic weak decay widths at high statistics with the
accuracy of ~5 % (stat) for both hypernuclei.Comment: 4pages, 4figures, International Conference on Hypernuclear and
Strange Particle Physics (HYP2003
Nucleon-nucleon coincidence measurement in the non-mesonic weak decay of 5_Lambda-He and 12_Lambda-C hypernuclei
We have measured both yields of neutron-proton and neutron-neutron pairs
emitted from the non-mesonic weak decay process of 5_Lambda-He and 12_Lambda-C
hypernuclei produced via the (pi^+,K^+) reaction for the first time. We
observed clean back-to-back correlation of the np- and nn-pairs in the
coincidence spectra for both hypernuclei. The ratio of those back-to-back pair
yields, Nnn / Nnp, must be close to the ratio of neutron- and proton-induced
decay widths of the decay, Gn(Lambda n -> nn)/Gp(Lambda p -> np). The obtained
ratios for each hypernuclei support recent calculations based on short-range
interactions.Comment: 4 pages, 1 figure, International Nuclear Physics Conference (INPC
2004), Goteborg, Sweden, June 27 - July 2, 2004, to appear in Nuclear Physics
Apparatus for a Search for T-violating Muon Polarization in Stopped-Kaon Decays
The detector built at KEK to search for T-violating transverse muon
polarization in K+ --> pi0 mu+ nu (Kmu3) decay of stopped kaons is described.
Sensitivity to the transverse polarization component is obtained from
reconstruction of the decay plane by tracking the mu+ through a toroidal
spectrometer and detecting the pi0 in a segmented CsI(Tl) photon calorimeter.
The muon polarization was obtained from the decay positron asymmetry of muons
stopped in a polarimeter. The detector included features which minimized
systematic errors while maintaining high acceptance.Comment: 56 pages, 30 figures, submitted to NI
Coincidence Measurement of the Nonmesonic Weak Decay of ^{12}_{Lambda}C
We have measured the angular correlation of the pair nucleons np and nn
emitted from the nonmesonic weak decay (NMWD) of ^{12}_{Lambda}C produced via
the (pi^+,K^+) reaction in coincidence measurement. The Lambda p -> np and
Lambda n -> nn modes were clearly identified by measuring the back-to-back
correlation of the emitted nucleon pairs which is the characteristic of
two-body kinematics. From the measured nucleon pair numbers N_{nn} and N_{np},
the ratio Gamma_n/Gamma_p of the partial decay widths Gamma_n(Lambda n -> nn)
and Gamma_p(Lambda p -> np) of ^{12}_{Lambda}C was extracted to be
0.51+-0.13(stat) +- 0.05(syst); this result is almost free from the ambiguity
due to the nuclear final state interaction and 3-body decay process, which were
inherent in the previous results. The obtained Gamma_n/Gamma_p ratio of
^{12}_{Lambda}C (p-shell) is close to that of ^5_{Lambda}He (s-shell). The
results are consistent with those of recent theoretical calculations.Comment: 13 pages, 4figures, 1 table,re-submitted to Physics Letters
Neutron and proton energy spectra from the non-mesonic weak decays of 5_Lambda-He and 12_Lambda-C
We have simultaneously measured the energy spectra of neutrons and protons
emitted in the non-mesonic weak decays of 5_Lambda-He and 12_Lambda-C
hypernuclei produced via the (pi^+,k^+) reaction with much higher statistics
over those of previous experiments. The neutron-to-proton yield ratios for both
hypernuclei at a high energy threshold (60 MeV) were approximately equal to
two, which suggests that the ratio of the neutron- and proton-induced decay
channels, Gn(Lambda n -> nn)/Gp(Lambda p -> np), is about 0.5. In the neutron
energy spectra, we found that the yield of the low-energy component is
unexpectedly large, even for 5_Lambda-He.Comment: 13pages, 4figures, submitted to Physics Letters
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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