6,497 research outputs found
Decoherence and entropy of primordial fluctuations II. The entropy budget
We calculate the entropy of adiabatic perturbations associated with a
truncation of the hierarchy of Green functions at the first non trivial level,
i.e. in a self-consistent Gaussian approximation. We give the equation
governing the entropy growth and discuss its phenomenology. It is parameterized
by two model-dependent kernels. We then examine two particular inflationary
models, one with isocurvature perturbations, the other with corrections due to
loops of matter fields. In the first model the entropy grows rapidely, while in
the second the state remains pure (at one loop).Comment: 28 page
Equine sarcoids: Bovine Papillomavirus type 1 transformed fibroblasts are sensitive to cisplatin and UVB induced apoptosis and show aberrant expression of p53
Bovine papillomavirus type 1 infects not only cattle but also equids and is a causative factor in the pathogenesis of
commonly occurring equine sarcoid tumours. Whilst treatment of sarcoids is notoriously difficult, cisplatin has been
shown to be one of the most effective treatment strategies for sarcoids. In this study we show that in equine
fibroblasts, BPV-1 sensitises cells to cisplatin-induced and UVB-induced apoptosis, a known cofactor for
papillomavirus associated disease, however BPV-1 transformed fibroblasts show increased clonogenic survival, which
may potentially limit the therapeutic effects of repeated cisplatin treatment. Furthermore we show that BPV-1
increases p53 expression in sarcoid cell lines and p53 expression can be either nuclear or cytoplasmic. The
mechanism and clinical significance of increase/abnormal p53 expression remains to be established
Luther-Emery Phase and Atomic-Density Waves in a Trapped Fermion Gas
The Luther-Emery liquid is a state of matter that is predicted to occur in
one-dimensional systems of interacting fermions and is characterized by a
gapless charge spectrum and a gapped spin spectrum. In this Letter we discuss a
realization of the Luther-Emery phase in a trapped cold-atom gas. We study by
means of the density-matrix renormalization-group technique a two-component
atomic Fermi gas with attractive interactions subject to parabolic trapping
inside an optical lattice. We demonstrate how this system exhibits compound
phases characterized by the coexistence of spin pairing and atomic-density
waves. A smooth crossover occurs with increasing magnitude of the atom-atom
attraction to a state in which tightly bound spin-singlet dimers occupy the
center of the trap. The existence of atomic-density waves could be detected in
the elastic contribution to the light-scattering diffraction pattern.Comment: 10 pages, 3 figures, 1 Table, submitted to Phys. Rev. on July 25th
200
- …