1,307 research outputs found
Proton Decay from Excited States in Spherical Nuclei
Based on a single particle model which describes the time evolution of the
wave function during tunneling across a one dimensional potential barrier we
study the proton decay of Pb from excited states with non-vanishing
angular momentum . Several quantities of interest in this process like
the decay rate , the period of oscillation , the transient
time , the tunneling time and the average value of the proton
packet position are computed and compared with the WKB results.Comment: 12 pages, 4 figure
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Soluble levels of receptor for advanced glycation endproducts and dysfunctional high-density lipoprotein in persons infected with human immunodeficiency virus: ACTG NWCS332.
The role of high-density lipoprotein (HDL) function and advanced glycation end products (AGEs) in HIV-related atherosclerotic cardiovascular disease (CVD) is unclear. Both glycation and oxidation (HDLox) are major modifications of HDL that can alter its composition and function. Therefore, we explored the longitudinal association of HDLox with progression of glycation, as evaluated by measurement of circulating forms of receptor for AGE that predict morbidity (soluble Receptors for Advanced Glycation Endproducts [sRAGE], endogenous secretory Receptors for Advanced Glycation Endproducts [esRAGE]), in people with HIV-1 (PWH; HIV-1) and uninfected (HIV-1) individuals.We retrospectively assessed if levels of plasma sRAGE and esRAGE and HDL function (reduced antioxidant function is associated with increased HDL lipid hydroperoxide content; HDLox) in a subset of participants (n = 80) from a prospective 3-year study (AIDS Clinical Trials Group A5078). Primary outcomes were baseline and yearly rates of change over 96 of 144 weeks (Δ) in HDLox in HIV-1 versus uninfected HIV-1 controls (noted as HIV-1).Higher baseline levels of sRAGE in PWH on effective anti-retroviral therapy and with low CVD risk, but not in HIV-1 persons, were independently associated with higher HDLox. EsRAGE, but not sRAGE, had consistent inverse relationships with ΔHDLox in both HIV-1 and HIV-1 persons at baseline. In HIV-1 but not in HIV-1 persons, ΔHDLox had positive and inverse relationships with ΔRAGE and ΔesRAGE, respectively.Glycation and oxidation of HDL may contribute to impaired HDL function present in PWH
Shake-Modified Resonant Autoionization In Magnesium
Anomalous features in the resonantly excited 2p autoionization spectrum of Mg are attributed to overlapping shake transitions of the excited bound (spectator) electron. Universal features of the shake spectrum are displayed and related to the post-collision interaction
Quantum Chaos and Regularity in Ultracold Fermi Gases
Quantum fluctuation of the energy is studied for an ultracold gas of
interacting fermions trapped in a three-dimensional potential. Periodic-orbit
theory is explored, and energy fluctuations are studied versus particle number
for generic regular and chaotic systems, as well for a system defined by a
harmonic confinement potential. Temperature effects on the energy fluctuations
are investigated.Comment: 4 pages, 5 figure
The ab initio no-core shell model
This contribution reviews a number of applications of the ab initio no-core
shell model (NCSM) within nuclear physics and beyond. We will highlight a
nuclear-structure study of the A = 12 isobar using a chiral NN + 3NF
interaction. In the spirit of this workshop we will also mention the new
development of the NCSM formalism to describe open channels and to approach the
problem of nuclear reactions. Finally, we will illustrate the universality of
the many-body problem by presenting the recent adaptation of the NCSM
effective-interaction approach to study the many-boson problem in an external
trapping potential with short-range interactions.Comment: 4 pages. Article based on the presentation by C. Forssen at the Fifth
Workshop on Critical Stability, Erice, Sicily. Published in Few-Body System
Tests and applications of self-consistent cranking in the interacting boson model
The self-consistent cranking method is tested by comparing the cranking
calculations in the interacting boson model with the exact results obtained
from the SU(3) and O(6) dynamical symmetries and from numerical
diagonalization. The method is used to study the spin dependence of shape
variables in the and boson models. When realistic sets of parameters
are used, both models lead to similar results: axial shape is retained with
increasing cranking frequency while fluctuations in the shape variable
are slightly reduced.Comment: 9 pages, 3 ps figures, Revte
FISSION DYNAMICS WITH MICROSCOPIC LEVEL DENSITIES
We present a consistent framework for treating the energy and angularmomentum dependence of the shape evolution in the nuclear fission. It combines microscopically calculated level densities with the Metropolis-walk method, has no new parameters, and can elucidate the energy-dependent influence of pairing and shell effects on the dynamics of warm nuclei
Energy averages and fluctuations in the decay out of superdeformed bands
We derive analytic formulae for the energy average (including the energy
average of the fluctuation contribution) and variance of the intraband decay
intensity of a superdeformed band. Our results may be expressed in terms of
three dimensionless variables: , ,
and . Here is
the spreading width for the mixing of a superdeformed (SD) state with the
normally deformed (ND) states whose spin is the same as 's. The
have mean level spacing and mean electromagnetic decay width
whilst has electromagnetic decay width .
The average decay intensity may be expressed solely in terms of the variables
and or, analogously to statistical
nuclear reaction theory, in terms of the transmission coefficients and
describing transmission from the to the SD band via and
to lower ND states.
The variance of the decay intensity, in analogy with Ericson's theory of
cross section fluctuations depends on an additional variable, the correlation
length
\Gamma_N/(\Gamma_S+\Gamma^{\downarrow})=\frac{d}{2\pi}T_N/(\Gamma_S+\Gamma^{\d
ownarrow}). This suggests that analysis of an experimentally obtained variance
could yield the mean level spacing as does analysis of the cross section
autocorrelation function in compound nuclear reactions.
We compare our results with those of Gu and Weidenm\"uller.Comment: revtex4, 14 pages, 4 figures, to appear in Physical Review
Metabolic: week 48 comparison of metabolic parameters and biomarkers in subjects receiving darunavir/ritonavir or atazanavir/ritonavir
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