1,834 research outputs found
Dielectric matrix and plasmon dispersion in strongly coupled electronic bilayer liquids
We develop a dielectric matrix and analyze plasmon dispersion in strongly
coupled charged-particle bilayers in the quantum domain. The formulation is
based on the classical quasi-localized charge approximation (QLCA) and extends
the QLCA formalism into the quantum domain. Its development, which parallels
that of 2D companion paper [Phys. Rev. E 70, 026406 (2004)] by three of the
authors, generalizes the single-layer scalar formalism therein to a bilayer
matrix formalism. Using pair correlation function data generated from diffusion
Monte Carlo simulations, we calculate the dispersion of the in-phase and
out-of-phase plasmon modes over a wide range of in-layer coupling values and
layer spacings. The out-of-phase spectrum exhibits an exchange-correlation
induced long-wavelength energy gap in contrast to earlier predictions of
acoustic dispersion softened by exchange-correlations. The energy gap is
similar to what has been previously predicted for classical charged-particle
bilayers and subsequently confirmed by recent molecular dynamics computer
simulations.Comment: 53 pages including 15 Figures with their captions. Submitted to
Physical Review
Properties of nonaqueous electrolytes Quarterly report, 20 Jun. - 19 Sep. 1967
Electrolyte preparation, and physical property and nuclear magnetic resonance structural studies of nonaqueous electrolyte
Single shot parameter estimation via continuous quantum measurement
We present filtering equations for single shot parameter estimation using
continuous quantum measurement. By embedding parameter estimation in the
standard quantum filtering formalism, we derive the optimal Bayesian filter for
cases when the parameter takes on a finite range of values. Leveraging recent
convergence results [van Handel, arXiv:0709.2216 (2008)], we give a condition
which determines the asymptotic convergence of the estimator. For cases when
the parameter is continuous valued, we develop quantum particle filters as a
practical computational method for quantum parameter estimation.Comment: 9 pages, 5 image
A theory of the infinite horizon LQ-problem for composite systems of PDEs with boundary control
We study the infinite horizon Linear-Quadratic problem and the associated
algebraic Riccati equations for systems with unbounded control actions. The
operator-theoretic context is motivated by composite systems of Partial
Differential Equations (PDE) with boundary or point control. Specific focus is
placed on systems of coupled hyperbolic/parabolic PDE with an overall
`predominant' hyperbolic character, such as, e.g., some models for
thermoelastic or fluid-structure interactions. While unbounded control actions
lead to Riccati equations with unbounded (operator) coefficients, unlike the
parabolic case solvability of these equations becomes a major issue, owing to
the lack of sufficient regularity of the solutions to the composite dynamics.
In the present case, even the more general theory appealing to estimates of the
singularity displayed by the kernel which occurs in the integral representation
of the solution to the control system fails. A novel framework which embodies
possible hyperbolic components of the dynamics has been introduced by the
authors in 2005, and a full theory of the LQ-problem on a finite time horizon
has been developed. The present paper provides the infinite time horizon
theory, culminating in well-posedness of the corresponding (algebraic) Riccati
equations. New technical challenges are encountered and new tools are needed,
especially in order to pinpoint the differentiability of the optimal solution.
The theory is illustrated by means of a boundary control problem arising in
thermoelasticity.Comment: 50 pages, submitte
Properties of nonaqueous electrolytes Sixth summary report, 20 Sep. 1967 - 19 Mar. 1968
Physical properties and structural studies on propylene carbonate, dimethyl formamide, and acetonitrile solvent electrolyte
The equation of state in lattice QCD: with physical quark masses towards the continuum limit
The equation of state of QCD at vanishing chemical potential as a function of
temperature is determined for two sets of lattice spacings. Coarser lattices
with temporal extension of N_t=4 and finer lattices of N_t=6 are used. Symanzik
improved gauge and stout-link improved staggered fermionic actions are applied.
The results are given for physical quark masses both for the light quarks and
for the strange quark. Pressure, energy density, entropy density, quark number
susceptibilities and the speed of sound are presented.Comment: 14 pages, 9 figures. Version published in JHEP: discussions added in
Sects. 1, 2. Fig. 1 changed and a new figure for the interaction measure
added. Information on statistics added in Table 1. Raw values of the pressure
added in Table 3. A few references adde
RNAi Screen Reveals an Abl Kinase-Dependent Host Cell Pathway Involved in Pseudomonas aeruginosa Internalization
Internalization of the pathogenic bacterium Pseudomonas aeruginosa by non-phagocytic cells is promoted by rearrangements of the actin cytoskeleton, but the host pathways usurped by this bacterium are not clearly understood. We used RNAi-mediated gene inactivation of ∼80 genes known to regulate the actin cytoskeleton in Drosophila S2 cells to identify host molecules essential for entry of P. aeruginosa. This work revealed Abl tyrosine kinase, the adaptor protein Crk, the small GTPases Rac1 and Cdc42, and p21-activated kinase as components of a host signaling pathway that leads to internalization of P. aeruginosa. Using a variety of complementary approaches, we validated the role of this pathway in mammalian cells. Remarkably, ExoS and ExoT, type III secreted toxins of P. aeruginosa, target this pathway by interfering with GTPase function and, in the case of ExoT, by abrogating P. aeruginosa–induced Abl-dependent Crk phosphorylation. Altogether, this work reveals that P. aeruginosa utilizes the Abl pathway for entering host cells and reveals unexpected complexity by which the P. aeruginosa type III secretion system modulates this internalization pathway. Our results furthermore demonstrate the applicability of using RNAi screens to identify host signaling cascades usurped by microbial pathogens that may be potential targets for novel therapies directed against treatment of antibiotic-resistant infections
Phases in Strongly Coupled Electronic Bilayer Liquids
The strongly correlated liquid state of a bilayer of charged particles has
been studied via the HNC calculation of the two-body functions. We report the
first time emergence of a series of structural phases, identified through the
behavior of the two-body functions.Comment: 5 pages, RevTEX 3.0, 4 ps figures; Submitted to Phys. Rev. Let
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