4,808 research outputs found
Experimental observation of nonclassical effects on single-photon detection rates
It is often asserted that quantum effects can be observed in coincidence
detection rates or other correlations, but never in the rate of single-photon
detection. We observe nonclassical interference in a singles rate, thanks to
the intrinsic nonlinearity of photon counters. This is due to a dependence of
the effective detection efficiency on the quantum statistics of the light beam.
Such measurements of detector response to photon pairs promise to shed light on
the microscopic aspects of silicon photodetectors, and on general issues of
quantum measurement and decoherence.Comment: 8 pages, 4 figure
El Plan Estratégico y el Desarrollo Económico Local de la Ciudad de Córdoba, Argentinade
The Strategic Plan of CĂłrdoba (PEC) is one of the few strategic urban development
plans in Latin America which has actually been implemented in the majority of its
components. The PEC was conceived as a collective and global project of the city as a
whole without excessive protagonism or special ownership by a few. The PEC integrated
a policy of public works – oriented at the “social debt” which existed in the city – with a
work on urbanistic norms and directions and economic development. The PEC as a
space for articulation achieved to organise a great number of representatives from civil
society organisations, achieving legitimacy and representation in the work of the PEC
Purinergic Modulation of Interleukin-1β Release from Microglial Cells Stimulated with Bacterial Endotoxin
Microglial cells express a peculiar plasma membrane receptor for extracellular ATP, named P2Z/P2X7 purinergic receptor, that triggers massive transmembrane ion fluxes and a reversible permeabilization of the plasma membrane to hydrophylic molecules of up to 900 dalton molecule weight and eventual cell death (Di Virgilio, F. 1995. Immunol. Today. 16:524–528). The physiological role of this newly cloned (Surprenant, A., F. Rassendren, E. Kawashima, R.A. North and G. Buell. 1996. Science (Wash. DC). 272:735–737) cytolytic receptor is unknown. In vitro and in vivo activation of the macrophage and microglial cell P2Z/P2X7 receptor by exogenous ATP causes a large and rapid release of mature IL-1β. In the present report we investigated the role of microglial P2Z/P2X7 receptor in IL-1β release triggered by LPS. Our data suggest that LPS-dependent IL-1β release involves activation of this purinergic receptor as it is inhibited by the selective P2Z/P2X7 blocker oxidized ATP and modulated by ATP-hydrolyzing enzymes such as apyrase or hexokinase. Furthermore, microglial cells release ATP when stimulated with LPS. LPS-dependent release of ATP is also observed in monocyte-derived human macrophages. It is suggested that bacterial endotoxin activates an autocrine/paracrine loop that drives ATP-dependent IL-1β secretion
Deferiprone versus Deferoxamine in Sickle Cell Disease: Results from a 5-year long-term Italian multi-center randomized clinical trial.
Blood transfusion and iron chelation currently represent a supportive therapy to manage anemia, vasculopathy and vaso-occlusion crises in Sickle-Cell-Disease. Here we describe the first 5-year long-term randomized clinical trial comparing Deferiprone versus Deferoxamine in patients with Sickle-Cell-Disease. The results of this study show that Deferiprone has the same effectiveness as Deferoxamine in decreasing body iron burden, measured as repeated measurements of serum ferritin concentrations on the same patient over 5-years and analyzed according to the linear mixed-effects model (LMM) (p=0.822). Both chelators are able to decrease, significantly, serum ferritin concentrations, during 5-years, without any effect on safety (p=0.005). Moreover, although the basal serum ferritin levels were higher in transfused compared with non-transfused group (p=0.031), the changes over time in serum ferritin levels were not statistically significantly different between transfused and non-transfused cohort of patients (p=0.389). Kaplan-Meier curve, during 5-years of study, suggests that Deferiprone does not alter survival in comparison with Deferoxamine (p=0.38). In conclusion, long-term iron chelation therapy with Deferiprone was associated with efficacy and safety similar to that of Deferoxamine. Therefore, in patients with Sickle-Cell-Disease, Deferiprone may represent an effective long-term treatment option
Local P Violation Effects and Thermalization in QCD: Views from Quantum Field Theory and Holography
We argue that the local violation of P and CP invariance in heavy ion
collisions and the universal thermal aspects observed in high energy collisions
are in fact two sides of the same coin, and both are related to quantum
anomalies of QCD. We argue that the low energy relations representing the
quantum anomalies of QCD are saturated by coherent low dimensional vacuum
configurations as observed in Monte Carlo lattice studies. The thermal spectrum
and approximate universality of the temperature with no dependence on energy of
colliding particles in this framework is due to the fact that the emission
results from the distortion of these low dimensional vacuum sheets rather than
from the colliding particles themselves. The emergence of the long- range
correlations of P odd domains (a feature which is apparently required for
explanation of the asymmetry observed at RHIC and LHC) is also a result of the
same distortion of the QCD vacuum configurations. We formulate the
corresponding physics using the effective low energy effective Lagrangian. We
also formulate the same physics in terms of the dual holographic picture when
low-dimensional sheets of topological charge embedded in 4d space, as observed
in Monte Carlo simulations, are identified with D2 branes. Finally, we argue
that study of these long range correlations in heavy ion collisions could serve
as a perfect test of a proposal that the observed dark energy in present epoch
is a result of a tiny deviation of the QCD vacuum energy in expanding universe
from its conventional value in Minkowski spacetime.Comment: final version to appear in Nucl.Phys.
P and CP Violation and New Thermalization Scenario in Heavy Ion Collisions
The violation of local P and CP invariance in QCD, as it is observed at RHIC,
has been a subject of intense discussions for the last couple of
years.Separately, a new thermalization scenario for heavy ion collisions
through the event horizon as a manifestation of the Unruh effect, has been also
suggested. In this paper we argue that these two, naively unrelated phenomena,
are actually two sides of the same coin as they are deeply rooted into the same
fundamental physics related to some very nontrivial topological features of
QCD. We formulate the universality conjecture for P and CP odd effects in heavy
ion collisions analogous to the universal thermal behaviour observed in all
other high energy interactions.Comment: Matches the journal versio
Multiplicative slices, relativistic Toda and shifted quantum affine algebras
We introduce the shifted quantum affine algebras. They map homomorphically
into the quantized -theoretic Coulomb branches of SUSY
quiver gauge theories. In type , they are endowed with a coproduct, and they
act on the equivariant -theory of parabolic Laumon spaces. In type ,
they are closely related to the open relativistic quantum Toda lattice of type
.Comment: 125 pages. v2: references updated; in section 11 the third local Lax
matrix is introduced. v3: references updated. v4=v5: 131 pages, minor
corrections, table of contents added, Conjecture 10.25 is now replaced by
Theorem 10.25 (whose proof is based on the shuffle approach and is presented
in a new Appendix). v6: Final version as published, references updated,
footnote 4 adde
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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