2,356 research outputs found
An Analytic Solution of Hydrodynamic Equations with Source Terms in Heavy Ion Collisions
The energy and baryon densities in heavy ion collisions are estimated by
analytically solving a 1+1 dimensional hydrodynamical model with source terms.
Particularly, a competition between the energy and baryon sources and the
expansion of the system is discussed in detail.Comment: LaTeX2e, 7 pages, 4 postscript figures, submitted to Int. J. Mod.
Phys.
Deconfinement Phase Transition in an Expanding Quark system in Relaxation Time Approximation
We investigated the effects of nonequilibrium and collision terms on the
deconfinement phase transition of an expanding quark system in Friedberg-Lee
model in relaxation time approximation. By calculating the effective quark
potential, the critical temperature of the phase transition is dominated by the
mean field, while the collisions among quarks and mesons change the time
structure of the phase transition significantly.Comment: 7 pages, 7 figure
Up-regulation of CNDP2 facilitates the proliferation of colon cancer
BACKGROUND: Cytosolic nonspecific dipetidase (CN2) belongs to the family of M20 metallopeptidases. It was stated in previous articles that higher expression levels of CN2 were observed in renal cell carcinoma and breast cancer. Our study explored the correlation between CN2 and colon carcinogenesis. METHODS: We analysed the relationship between 183 patients clinicopathological characteristics and its CN2 expression. To detect the levels of CN2 in colon cancer cell lines and colon cancer tissues by western blot. To verify cell proliferation in colon cancer cells with knockdown of CNDP2 and explore the causes of these phenomena. RESULTS: The expression levels of CN2 in clinical colon tumors and colon cancer cell lines were significantly higher than that in normal colon mucosa and colon cell lines. The difference in CN2 levels was associated with tumor location (right- and left-sided colon cancer), but there was no significant association with age, gender, tumor size, tumor grade, tumor stage or serum carcinoembryonic antigen (CEA). Knockdown of CNDP2 inhibited cell proliferation, blocked cell cycle progression and retarded carcinogenesis in an animal model. The signaling pathway through which knockdown of CNDP2 inhibited cell proliferation and tumorigenesis involved in EGFR, cyclin B1 and cyclin E. CONCLUSIONS: Knockdown of CNDP2 can inhibit the proliferation of colon cancer in vitro and retarded carcinogenesis in vivo
Thermal and Nonthermal Pion Enhancements with Chiral Symmetry Restoration
The pion production by sigma decay and its relation with chiral symmetry
restoration in a hot and dense matter are investigated in the framework of the
Nambu-Jona-Lasinio model. The decay rate for the process sigma -> 2pion to the
lowest order in a 1/N_c expansion is calculated as a function of temperature T
and chemical potential mu. The thermal and nonthermal enhancements of pions
generated by the decay before and after the freeze-out present only in the
crossover region of the chiral symmetry transition. The strongest nonthermal
enhancement is located in the vicinity of the endpoint of the first-order
transition.Comment: Latex2e, 12 pages, 8 Postscript figures, submitted to Phys. Rev.
Microbial functional trait of rRNA operon copy numbers increases with organic levels in anaerobic digesters.
The ecological concept of the r-K life history strategy is widely applied in macro-ecology to characterize functional traits of taxa. However, its adoption in microbial communities is limited, owing to the lack of a measureable, convenient functional trait for classification. In this study, we performed an experiment of stepwise organic amendments in triplicate anaerobic digesters. We found that high resource availability significantly favored microbial r-strategists such as Bacillus spp. Incremental resource availability heightened average rRNA operon copy number of microbial community, resulting in a strong, positive correlation (r>0.74, P<0.008). This study quantifies how resource availability manipulations influence microbial community composition and supports the idea that rRNA operon copy number is an ecologically meaningful trait which reflects resource availability
Black-Hole Perturbation Plus Post-Newtonian Theory: Hybrid Waveform for Neutron Star Binaries
We consider the motion of nonspinning, compact objects orbiting around a Kerr
black hole with tidal couplings. The tide-induced quadrupole moment modifies
both the orbital energy and outgoing fluxes, so that over the inspiral
timescale there is an accumulative shift in the orbital and gravitational wave
phase. Previous studies on compact object tidal effects have been carried out
in the Post-Newtonian (PN) and Effective-One-Body (EOB) formalisms. In this
work, within the black hole perturbation framework, we propose to characterize
the tidal influence in the expansion of mass ratios, while higher-order PN
corrections are naturally included. For the equatorial and circular orbit, we
derive the leading order, frequency dependent tidal phase shift which agrees
with the Post-Newtonian result at low frequencies but deviates at high
frequencies. We also find that such phase shift has weak dependence () on the spin of the primary black hole. Combining this black hole
perturbation waveform with the Post-Newtonian waveform, we propose a
frequency-domain, hybrid waveform that shows comparable accuracy as the EOB
waveform in characterizing the tidal effects, as calibrated by numerical
relativity simulations. Further improvement is expected as the next-leading
order in mass ratio and the higher-PN tidal corrections are included. This
hybrid approach is also applicable for generating binary black hole waveforms.Comment: 20 pages, 5 figure
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