1,676 research outputs found
Remarks on a Proposed Super-Kamiokande Test for Quantum Gravity Induced Decoherence Effects
Lisi, Marrone, and Montanino have recently proposed a test for quantum
gravity induced decoherence effects in neutrino oscillations observed at
Super-Kamiokande. We comment here that their equations have the same
qualitative form as the energy conserving objective state vector reduction
equations discussed by a number of authors. However, using the Planckian
parameter value proposed to explain state vector reduction leads to a neutrino
oscillation effect many orders of magnitude smaller than would be detectable at
Super-Kamiokande. Similar estimates hold for the Ghirardi, Rimini, and Weber
spontaneous localization approach to state vector reduction, and our remarks
are relevant as well to proposed meson and meson tests of gravity
induced decoherence.Comment: 10 pages, plain Tex, no figure
Apoptosis of Dedifferentiated Hepatoma Cells is Independent of NF-jB Activation in Response to LPS
Dedifferentiated hepatoma cells, in contrast to most other cell types including hepatoma cells, undergo apoptosis when treated with lipopolysaccharide (LPS) plus the protein synthesis inhibitor cycloheximide (CHx). We recently reported that the dedifferentiated hepatoma cells also exhibit a strong and prolonged NF-jB induction phenotype upon exposure to LPS, suggesting that NF-jB signaling may play a pro-survival role, as reported in several other cell systems. To test the role of NF-jB in preventing LPS-mediated apoptosis, we examined the dedifferentiated cell line M38. Results show that antioxidants strongly inhibited LPS + CHx-mediated cell death in the M38 cells, yet only modestly inhibited NF-jB induction. In addition, inhibition of NF-jB translocation by infection of the M38 cells with an adenoviral vector expressing an IjBa super-repressor did not result in LPS-mediated cell death. These results suggest that unlike TNFa induction, the cell survival pathway activated in response to LPS is independent of NF-jB translocation in the dedifferentiated cells. Addition of inhibitors of JNK, p38 and ERK pathways also failed to elicit LPS-mediated apoptosis similar to that observed when protein synthesis is prevented. Thus, cell survival pathways other than those involving NF-jB inducible gene expression or other well-known pathways appear to be involved in protecting the dedifferentiated hepatoma variant cells from LPS-mediated apoptosis. Importantly, this pro-apoptotic function of LPS appears to be a function of loss of hepatic gene expression, as the parental hepatoma cells resist LPSmediated apoptosis in the presence of protein synthesis inhibitors
Coulomb Phase Gluon Scattering at Strong Coupling
We calculate corrections to gluon scattering amplitudes in a Coulomb phase
using gauge/string duality. The Coulomb phase considered is a maximal rank
breaking of . This problem
therefore has 3 scales involved: 1) the scale of the massive fields
arising from the spontaneous breaking of the gauge group; 2) The scale of the
scattering, characterized by the Mandelstam variables ; 3) The IR
regulator . We find corrections in the hard scattering limit , and also find below threshold corrections
with . We find that the corrections in the second case
are finite, and so are IR regulator independent.Comment: 17+17 pages, 3 figure
Virtual SUSY Threshold Effects and CDF large Anomaly
Recent CDF data of the inclusive jet cross section shows threshold-like
structured deviation, around transverse momentum
GeV. If this data is real, not just some statistical fluctuation, is it
possible to interpret the anomaly in terms of virtual SUSY effects? The purpose
of this note is to address this question. However, we find that virtual SUSY
loop interference effects [near the threshold] are too small to explain the CDF
data. Our main conclusion seems to be on the right track if we assume that the
recent global analysis of improved parton distributions by Lai et al. is
correct. PACS number(s): 14.65.Ha, 12.38.Bx, 12.60.Jv, 13.85.-tComment: 10 pages, RevTex, 1 Tex file and 5-page postscript together, To
appear in Phys.Lett.
An open quantum system approach to EPR correlations in K0-K0 system
We find the time evolution of the system of two non-interacting unstable
particles, distinguishable as well as identical ones, in arbitrary reference
frame having only the Kraus operators governing the evolution of its components
in the rest frame. We than calculate in the rigorous way
Einstein-Podolsky-Rosen quantum correlation functions for K0-K0 system in the
singlet state taking into account CP-violation and decoherence and show that
the results are exactly the same despite the fact we treat kaons as
distinguishable or identical particles which means that the statistics of the
particles plays no role, at least in considered cases.Comment: 14 pp. no fig
Sterile neutrinos in tau lepton decays
We study possible contributions of heavy sterile neutrinos to the
decays . From the experimental
upper bounds on their rates we derive new constraints on the
mixing in the mass region MeV. We discuss
cosmological and astrophysical status of in this mass region and
compare our constraints with those recently derived by the NOMAD collaboration.Comment: 17 pages, 2 figure
Brane cosmology with an anisotropic bulk
In the context of brane cosmology, a scenario where our universe is a
3+1-dimensional surface (the ``brane'') embedded in a five-dimensional
spacetime (the ``bulk''), we study geometries for which the brane is
anisotropic - more specifically Bianchi I - though still homogeneous. We first
obtain explicit vacuum bulk solutions with anisotropic three-dimensional
spatial slices. The bulk is assumed to be empty but endowed with a negative
cosmological constant. We then embed Z_2-symmetric branes in the anisotropic
spacetimes and discuss the constraints on the brane energy-momentum tensor due
to the five-dimensional anisotropic geometry. We show that if the bulk is
static, an anisotropic brane cannot support a perfect fluid. However, we find
that for some of our bulk solutions it is possible to embed a brane with a
perfect fluid though its energy density and pressure are completely determined
by the bulk geometry.Comment: 20 pages, 1 figur
Brans-Dicke brane cosmology
A five dimensional brane cosmology with non-minimally coupled scalar field to
gravity has been considered in a Jordan-Brans-Dicke frame. We derive an
effective four dimensional field equations on a 3+1 dimensional brane where the
fifth dimension has been assumed to have an orbifold symmetry. We have noticed
that the evolution equation for the matter component stuck to the brane is
non-trivially coupled to the scalar field living on the brane and the bulk.
Finally we discuss some cosmological consequences of this set-up.Comment: 8 pages. Major revision. Conclusions where change
Economic development, human development, and the pursuit of happiness, April 1, 2, and 3, 2004
This repository item contains a single issue of the Pardee Conference Series, a publication series that began publishing in 2006 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. This was the Center's spring conference, which took place during April 1, 2, and 3, 2004.The conference asks the questions, how can we make sure that the benefits of economic growth flow into health, education, welfare, and other aspects of human development; and what is the relationship between human development and economic development? Speakers and participants discuss the role that culture, legal and political institutions, the UN Developmental Goals, the level of decision-making, and ethics, play in development
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