1,011 research outputs found
Quantum and classical correlations in waveguide lattices
We study quantum and classical Hanbury Brown-Twiss correlations in waveguide
lattices. We develop a theory for the propagation of photon pairs in the
lattice, predicting the emergence of nontrivial quantum interferences unique to
lattice systems. Experimentally, we observe the classical counterpart of these
interferences using intensity correlation measurements. We discuss the
correspondence between the classical and quantum correlations, and consider
path-entangled input states which do not have a classical analogue. Our results
demonstrate that waveguide lattices can be used as a robust and highly
controllable tool for manipulating quantum states, and offer new ways of
studying the quantum properties of light.Comment: Comments are welcom
The VERNALIZATION 2 Gene Mediates the Epigenetic Regulation of Vernalization in Arabidopsis
AbstractThe acceleration of flowering by a long period of low temperature, vernalization, is an adaptation that ensures plants overwinter before flowering. Vernalization induces a developmental state that is mitotically stable, suggesting that it may have an epigenetic basis. The VERNALIZATION2 (VRN2) gene mediates vernalization and encodes a nuclear-localized zinc finger protein with similarity to Polycomb group (PcG) proteins of plants and animals. In wild-type Arabidopsis, vernalization results in the stable reduction of the levels of the floral repressor FLC. In vrn2 mutants, FLC expression is downregulated normally in response to vernalization, but instead of remaining low, FLC mRNA levels increase when plants are returned to normal temperatures. VRN2 function therefore stably maintains FLC repression after a cold treatment, serving as a mechanism for the cellular memory of vernalization
Why pinning by surface irregularities can explain the peak effect in transport properties and neutron diffraction results in NbSe2 and Bi-2212 crystals?
The existence of a peak effect in transport properties (a maximum of the
critical current as function of magnetic field) is a well-known but still
intriguing feature of type II superconductors such as NbSe2 and Bi-2212. Using
a model of pinning by surface irregularities in anisotropic superconductors, we
have developed a calculation of the critical current which allows estimating
quantitatively the critical current in both the high critical current phase and
in the low critical current phase. The only adjustable parameter of this model
is the angle of the vortices at the surface. The agreement between the
measurements and the model is really very impressive. In this framework, the
anomalous dynamical properties close to the peak effect is due to co-existence
of two different vortex states with different critical currents. Recent neutron
diffraction data in NbSe2 crystals in presence of transport current support
this point of view
Comparison of Different Anthropometric Measurements and Inflammatory Biomarkers
Introduction. Different anthropometric variables have been shown to be related to cardiovascular morbidity and mortality. Our aim was to compare the association between different anthropometric measurements and inflammatory status. Methods and results. A cross-sectional study design in which we analyzed the data collected during a five-year period in the Tel Aviv Medical Center Inflammation Survey (TAMCIS). Included in the study were 13,033 apparently healthy individuals at a mean (SD) age of 43. Of these, 8,292 were male and 4,741 female. A significant age-adjusted and multiple-adjusted partial correlation was noted between all anthropometric measurements and all inflammatory biomarkers. There was no significant difference in the correlation coefficients between different biomarkers and anthropometric variables. Conclusion. Most of the common used anthropometric variables are similarly correlated with inflammatory variables. The clinician can choose the variable that he/she finds easiest to use
Equilibration and Dynamic Phase Transitions of a Driven Vortex Lattice
We report on the observation of two types of current driven transitions in
metastable vortex lattices. The metastable states, which are missed in usual
slow transport measurements, are detected with a fast transport technique in
the vortex lattice of undoped
2H-NbSe. The transitions are seen by following the evolution of these
states when driven by a current. At low currents we observe an equilibration
transition from a metastable to a stable state, followed by a dynamic
crystallization transition at high currents.Comment: 5 pages, 4 figure
Correction: Joint Effect of Habitat Identity and Spatial Distance on Spiders' Community Similarity in a Fragmented Transition Zone
[This corrects the article DOI: 10.1371/journal.pone.0168417.]
Large Charge Four-Dimensional Extremal N=2 Black Holes with R^2-Terms
We consider N=2 supergravity in four dimensions with small R^2 curvature
corrections. We construct large charge extremal supersymmetric and
non-supersymmetric black hole solutions in all space, and analyze their
thermodynamic properties.Comment: 18 pages. v2,3: minor fixe
Characterizing and Modeling Control-Plane Traffic for Mobile Core Network
In this paper, we first carry out to our knowledge the first in-depth
characterization of control-plane traffic, using a real-world control-plane
trace for 37,325 UEs sampled at a real-world LTE Mobile Core Network (MCN). Our
analysis shows that control events exhibit significant diversity in device
types and time-of-day among UEs. Second, we study whether traditional
probability distributions that have been widely adopted for modeling Internet
traffic can model the control-plane traffic originated from individual UEs. Our
analysis shows that the inter-arrival time of the control events as well as the
sojourn time in the UE states of EMM and ECM for the cellular network cannot be
modeled as Poisson processes or other traditional probability distributions. We
further show that the reasons that these models fail to capture the
control-plane traffic are due to its higher burstiness and longer tails in the
cumulative distribution than the traditional models. Third, we propose a
two-level hierarchical state-machine-based traffic model for UE clusters
derived from our adaptive clustering scheme based on the Semi-Markov Model to
capture key characteristics of mobile network control-plane traffic -- in
particular, the dependence among events generated by each UE, and the diversity
in device types and time-of-day among UEs. Finally, we show how our model can
be easily adjusted from LTE to 5G to support modeling 5G control-plane traffic,
when the sizable control-plane trace for 5G UEs becomes available to train the
adjusted model. The developed control-plane traffic generator for LTE/5G
networks is open-sourced to the research community to support high-performance
MCN architecture design R&D
Irreversible magnetization in thin YBCO films rotated in external magnetic field
The magnetization M of a thin YBaCuO film is measured as a function of the
angle between the applied field H and the c-axis. For fields above
the first critical field, but below the Bean's field for first penetration H*,
M is symmetric with respect to and the magnetization curves for
forward and backward rotation coincide. For H>H* the curves are asymmetric and
they do not coincide. These phenomena have a simple explanation in the
framework of the Bean critical state model.Comment: 14 pages, 7 PostScript figure
- …