12,713 research outputs found
Separable Structure of Many-Body Ground-State Wave Function
We have investigated a general structure of the ground-state wave function
for the Schr\"odinger equation for identical interacting particles (bosons
or fermions) confined in a harmonic anisotropic trap in the limit of large .
It is shown that the ground-state wave function can be written in a separable
form. As an example of its applications, this form is used to obtain the
ground-state wave function describing collective dynamics for trapped
bosons interacting via contact forces.Comment: J. Phys. B: At. Mol. Opt. Phys. 33 (2000) (accepted for publication
Modulation of Negative Index Metamaterials in the Near-IR Range
Optical modulation of the effective refractive properties of a "fishnet"
metamaterial with a Ag/Si/Ag heterostructure is demonstrated in the near-IR
range and the associated fast dynamics of negative refractive index is studied
by pump-probe method. Photo excitation of the amorphous Si layer at visible
wavelength and corresponding modification of its optical parameters is found to
be responsible for the observed modulation of negative refractive index in
near-IR.Comment: 11 figures, 4 figure
Comment on "Antilocalization in a 2D Electron Gas in a Random Magnetic Field"
In a recent Letter, Taras-Semchuk and Efetov reconsider the problem of
electron localization in a random magnetic field in two dimensions. They claim
that due to the long-range nature of the vector potential correlations an
additional term appears in the effective field theory (-model) of the
problem, leading to delocalization at the one-loop level. This calls into
question the results of earlier analytical studies, where the random magnetic
field problem was mapped onto the conventional unitary-class -model,
implying that the leading quantum correction is of two-loop order and of a
localizing nature. We show in this Comment, however, that the new term in fact
does not exist and was erroneously obtained by Taras-Semchuk and Efetov because
of an inconsistent treatment violating gauge invariance.Comment: 1 page, 2 figure
Reciprocity as deliberative capacity: lessons from a citizens deliberation on carbon pricing mechanisms in Australia
Australia has seen a deep division in opinion in search of a carbon pricing mechanism. While concepts of carbon taxation and emission trading have comparable public support, climate scepticism is influencing the debates in political and public spheres in downplaying the need for carbon pricing. Public deliberation is a possible engagement option to address the conflict inherent in climate policy preferences. This research explores the way that a deliberative forum involving twenty-four Australians promoted effective communication between participants through which conflict between policy preferences became more tangible. While the forum did not eliminate disagreement in preferences in the choice of carbon pricing mechanisms, participants reached consensus on fundamental principles such as the need for trusted sources of information, trusted governance procedures, and transparent accountability by appropriate institutions. Shared political expectations encouraged dialogue and cooperation in discussions by enhancing reciprocal understanding. Two sceptical participants who originally had strong opinions different from the rest of the group managed to find common ground. Public deliberative forums that are conducive to reciprocal communication are able to provide a mechanism for joint problem-solving processes that are less adversarial and more responsive to the range of people\u27s preferences. Keywords: public deliberation, consensus, emission trading, carbon tax, deliberative democracy, Australi
Netons: Vibrations of Complex Networks
We consider atoms interacting each other through the topological structure of
a complex network and investigate lattice vibrations of the system, the quanta
of which we call {\em netons} for convenience. The density of neton levels,
obtained numerically, reveals that unlike a local regular lattice, the system
develops a gap of a finite width, manifesting extreme rigidity of the network
structure at low energies. Two different network models, the small-world
network and the scale-free network, are compared: The characteristic structure
of the former is described by an additional peak in the level density whereas a
power-law tail is observed in the latter, indicating excitability of netons at
arbitrarily high energies. The gap width is also found to vanish in the
small-world network when the connection range .Comment: 9 pages, 6 figures, to appear in JP
The Potential Trajectory of Carbapenem-Resistant Enterobacteriaceae, an Emerging Threat to Health-Care Facilities, and the Impact of the Centers for Disease Control and Prevention Toolkit.
Carbapenem-resistant Enterobacteriaceae (CRE), a group of pathogens resistant to most antibiotics and associated with high mortality, are a rising emerging public health threat. Current approaches to infection control and prevention have not been adequate to prevent spread. An important but unproven approach is to have hospitals in a region coordinate surveillance and infection control measures. Using our Regional Healthcare Ecosystem Analyst (RHEA) simulation model and detailed Orange County, California, patient-level data on adult inpatient hospital and nursing home admissions (2011-2012), we simulated the spread of CRE throughout Orange County health-care facilities under 3 scenarios: no specific control measures, facility-level infection control efforts (uncoordinated control measures), and a coordinated regional effort. Aggressive uncoordinated and coordinated approaches were highly similar, averting 2,976 and 2,789 CRE transmission events, respectively (72.2% and 77.0% of transmission events), by year 5. With moderate control measures, coordinated regional control resulted in 21.3% more averted cases (n = 408) than did uncoordinated control at year 5. Our model suggests that without increased infection control approaches, CRE would become endemic in nearly all Orange County health-care facilities within 10 years. While implementing the interventions in the Centers for Disease Control and Prevention's CRE toolkit would not completely stop the spread of CRE, it would cut its spread substantially, by half
Direct measurement of non-linear properties of bipartite quantum states
Non-linear properties of quantum states, such as entropy or entanglement,
quantify important physical resources and are frequently used in quantum
information science. They are usually calculated from a full description of a
quantum state, even though they depend only on a small number parameters that
specify the state. Here we extract a non-local and a non-linear quantity,
namely the Renyi entropy, from local measurements on two pairs of polarization
entangled photons. We also introduce a "phase marking" technique which allows
to select uncorrupted outcomes even with non-deterministic sources of entangled
photons. We use our experimental data to demonstrate the violation of entropic
inequalities. They are examples of a non-linear entanglement witnesses and
their power exceeds all linear tests for quantum entanglement based on all
possible Bell-CHSH inequalities.Comment: To appear on PRL with minor change
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Dissecting the regulatory strategies of NF-kB RelA target genes in the inflammatory response reveals differential transactivation logics
Nuclear factor κB (NF-κB) RelA is the potent transcriptional activator of inflammatory response genes. We stringently defined a list of direct RelA target genes by integrating physical (chromatin immunoprecipitation sequencing [ChIP-seq]) and functional (RNA sequencing [RNA-seq] in knockouts) datasets. We then dissected each gene’s regulatory strategy by testing RelA variants in a primary-cell genetic-complementation assay. All endogenous target genes require RelA to make DNA-base-specific contacts, and none are activatable by the DNA binding domain alone. However, endogenous target genes differ widely in how they employ the two transactivation domains. Through model-aided analysis of the dynamic time-course data, we reveal the gene-specific synergy and redundancy of TA1 and TA2. Given that post-translational modifications control TA1 activity and intrinsic affinity for coactivators determines TA2 activity, the differential TA logics suggests context-dependent versus context-independent control of endogenous RelA-target genes. Although some inflammatory initiators appear to require co-stimulatory TA1 activation, inflammatory resolvers are a part of the NF-κB RelA core response
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