849 research outputs found
A symmetry reduction technique for higher order Painlev\'e systems
The symmetry reduction of higher order Painlev\'e systems is formulated in
terms of Dirac procedure.
A set of canonical variables that admit Dirac reduction procedure is proposed
for Hamiltonian structures governing the and
Painlev\'e systems for .Comment: to appear in Phys. Lett.
Spectral and Timing Nature of the Symbiotic X-ray Binary 4U 1954+319: The Slowest Rotating Neutron Star in an X-ray Binary System
The symbiotic X-ray binary 4U 1954+319 is a rare system hosting a peculiar
neutron star (NS) and an M-type optical companion. Its ~5.4h NS spin period is
the longest among all known accretion-powered pulsars and exhibited large (~7%)
fluctuations over 8 years. A spin trend transition was detected with Swift/BAT
around an X-ray brightening in 2012. The source was in quiescent and bright
states before and after this outburst based on 60 ks Suzaku observations in
2011 and 2012. The observed continuum is well described by a Comptonized model
with the addition of a narrow 6.4 keV Fe Kalpha line during the outburst.
Spectral similarities to slowly rotating pulsars in high-mass X-ray binaries,
its high pulsed fraction (~60-80%), and the location in the Corbet diagram
favor high B-field (>~1e+12 G) over a weak field as in low-mass X-ray binaries.
The observed low X-ray luminosity (1e+33-1e+35 erg/s), probable wide orbit, and
a slow stellar wind of this SyXB make quasi-spherical accretion in the subsonic
settling regime a plausible model. Assuming a ~1e+13 G NS, this scheme can
explain the ~5.4 h equilibrium rotation without employing the magnetar-like
field (~1e+16 G) required in the disk accretion case. The time-scales of
multiple irregular flares (~50 s) can also be attributed to the free-fall time
from the Alfven shell for a ~1e+13 G field. A physical interpretation of SyXBs
beyond the canonical binary classifications is discussed.Comment: 20 pages, 18 figures, 3 tables, accepted for publication in the
Astrophysical Journa
Gamow-Teller strength distributions for double-beta-decaying nuclei within continuum-QRPA
A version of the pn-continuum-QRPA is outlined and applied to describe the
Gamow-Teller strength distributions for -decaying open-shell
nuclei. The calculation results obtained for the pairs of nuclei Cd-Sn
and Te-Xe are compared with available experimental data.Comment: 8 pages, 3 figures, To appear in the proceedings of "Nucleus-2007:
Fundamental problems of nuclear physics, atomic power engineering and nuclear
technologies" Voronezh, Russia, June 25-29, 200
Precision measurement of vector and tensor analyzing powers in elastic deuteron-proton scattering
High precision vector and tensor analyzing powers of elastic deuteron-proton
d+p scattering have been measured at intermediate energies to investigate
effects of three-nucleon forces (3NF). Angular distribution in the range of
70-120 degree in the center-of mass frame for incident-deuteron energies of 130
and 180 MeV were obtained using the RIKEN facility. The beam polarization was
unambiguously determined by measuring the 12C(d,alpha)10B(2+) reaction at 0
degree. Results of the measurements are compared with state-of-the-art
three-nucleon calculations. The present modeling of nucleon-nucleon forces and
its extension to the three-nucleon system is not sufficient to describe the
high precision data consistently and requires, therefore, further
investigation
Cell-penetrating peptides containing the progesterone receptor polyproline domain inhibits EGF signaling and cell proliferation in lung cancer cells.
Non-small cell lung cancer (NSCLC) accounts for the majority (80-85%) of all lung cancers. All current available treatments have limited efficacy. The epidermal growth factor receptor (EGFR) plays a critical role in the development and progression of NSCLC, with high EGFR expression associated with increased cell proliferation and poor prognosis. Thus, interfering with EGFR signaling has been shown to effectively reduce cell proliferation and help in the treatment of NSCLC. We previously demonstrated that the progesterone receptor (PR) contains a polyproline domain (PPD) that directly interacts with Src homology 3 (SH3) domain-containing molecules and expression of PR-PPD peptides inhibits NSCLC cell proliferation. In this study, we investigated whether the introduction of PR-PPD by cell-penetrating peptides (CPPs) could inhibit EGF-induced cell proliferation in NSCLC cells. PR-PPD was attached to a cancer-specific CPP, Buforin2 (BR2), to help deliver the PR-PPD into NSCLC cells. Interestingly, addition of BR2-2xPPD peptides containing two PR-PPD repeats was more effective in inhibiting NSCLC proliferation and significantly reduced EGF-induced phosphorylation of Erk1/2. BR2-2xPPD treatment induced cell cycle arrest by inhibiting the expression of cyclin D1 and CDK2 genes in EGFR-wild type A549 cells. Furthermore, the combination treatment of EGFR-tyrosine kinase inhibitors (TKIs), including Gefitinib or Erlotinib, with BR2-2xPPD peptides further suppressed the growth of NSCLC PC9 cells harboring EGFR mutations as compared to EGFR-TKIs treatment alone. Importantly, BR2-2xPPD peptides mediated growth inhibition in acquired Gefitinib- and Erlotinib- resistant lung adenocarcinoma cells. Our data suggests that PR-PPD is the minimal protein domain sufficient to inhibit NSCLC cell growth and has the potential to be developed as a novel NSCLC therapeutic agent
Lidar observation of ozone over Tsukuba (36 deg N, 140 deg E)
An ozone lidar system was installed at the National Institute for Environmental Studies (NIES) in Tsukuba, Japan in March 1988 and has been measuring vertical profiles of ozone (15 - 45 km) since September 1988. The lidar system consists of a XeCl (308 nm) excimer laser, its deuterium Raman shifter (339 nm), a XeF excimer laser (351 nm), a 2 m telescope, a receiving system and a data processing system. The precision of the derived ozone concentration is about 10 percent of an altitude of 40 km for a 4 hr observation. Temperature profiles (30 - 80 km) are also obtained from the Rayleigh scattering signals at 351 nm. Approximate 50 ozone measurements are carried out in a year and variations of vertical profiles of ozone such as seasonal variations and shorter-term variations are observed. Systematic errors due to aerosols had been negligible until the arrival of the stratospheric aerosols injected by the eruption of Mt. Pinatubo. Effects of the volcanic aerosols on ozone measurements depend on the differences between wavelengths used as the on- and off-resonance
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