Hydrostatics of a fluid between parallel plates at low bond numbers

Two-dimensional liquid vapor interface behavior between parallel plates under static equilibrium and low gravitational acceleratio

Out of Equilibrium Non-perturbative Quantum Field Dynamics in Homogeneous External Fields

The quantum dynamics of the symmetry broken lambda (Phi^2)^2 scalar field theory in the presence of an homogeneous external field is investigated in the large N limit. We choose as initial state the ground state for a constant external field J .The sign of the external field is suddenly flipped from J to - J at a given time and the subsequent quantum dynamics calculated. Spinodal instabilities and parametric resonances produce large quantum fluctuations in the field components transverse to the external field. This allows the order parameter to turn around the maximum of the potential for intermediate times. Subsequently, the order parameter starts to oscillate near the global minimum for external field - J, entering a novel quasi-periodic regime.Comment: LaTex, 30 pages, 12 .ps figures, improved version to appear in Phys Rev

Liquid-gas interface configurations in interconnected concentric cylinder tankage systems

Computer program for liquid-gas interface relations in interconnected concentric cylinder tankage system

Non-equilibrium dynamics in quantum field theory at high density: the tsunami

The dynamics of a dense relativistic quantum fluid out of thermodynamic equilibrium is studied in the framework of the Phi^4 scalar field theory in the large N limit. The time evolution of a particle distribution in momentum space (the tsunami) is computed. The effective mass felt by the particles in such a high density medium equals the tree level mass plus the expectation value of the squared field. The case of negative tree level squared mass is particularly interesting. In such case dynamical symmetry restoration as well as dynamical symmetry breaking can happen. Furthermore, the symmetry may stay broken with vanishing asymptotic squared mass showing the presence of out of equilibrium Goldstone bosons. We study these phenomena and identify the set of initial conditions that lead to each case. We compute the equation of state which turns to depend on the initial state. Although the system does not thermalize, the equation of state for asymptotically broken symmetry is of radiation type. We compute the correlation functions at equal times. The two point correlator for late times is the sum of different terms. One stems from the initial particle distribution. Another term accounts for the out of equilibrium Goldstone bosons created by spinodal unstabilities when the symmetry is asymptotically broken.Both terms are of the order of the inverse of the coupling for distances where causal signals can connect the two points. The contribution of the out of equilibrium Goldstones exhibits scaling behaviour in a generalized sense.Comment: LaTex, 49 pages, 15 .ps figure

Virtual Meson Cloud of the Nucleon and Intrinsic Strangeness and Charm

We have applied the Meson Cloud Model (MCM) to calculate the charm and strange antiquark distribution in the nucleon. The resulting distribution, in the case of charm, is very similar to the intrinsic charm momentum distribution in the nucleon. This seems to corroborate the hypothesis that the intrinsic charm is in the cloud and, at the same time, explains why other calculations with the MCM involving strange quark distributions fail in reproducing the low x region data. From the intrinsic strange distribution in the nucleon we have extracted the strangeness radius of the nucleon, which is in agreement with other meson cloud calculations.Comment: 9 pages RevTex, 4 figure

Caffeine blocks disruption of blood brain barrier in a rabbit model of Alzheimer's disease

High levels of serum cholesterol and disruptions of the blood brain barrier (BBB) have all been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease. Results from studies conducted in animals and humans suggest that caffeine might be protective against Alzheimer's disease but by poorly understood mechanisms. Using rabbits fed a cholesterol-enriched diet, we tested our hypothesis that chronic ingestion of caffeine protects against high cholesterol diet-induced disruptions of the BBB. New Zealand rabbits were fed a 2% cholesterol-enriched diet, and 3 mg caffeine was administered daily in drinking water for 12 weeks. Total cholesterol and caffeine concentrations from blood were measured. Olfactory bulbs (and for some studies hippocampus and cerebral cortex as well) were evaluated for BBB leakage, BBB tight junction protein expression levels, activation of astrocytes, and microglia density using histological, immunostaining and immunoblotting techniques. We found that caffeine blocked high cholesterol diet-induced increases in extravasation of IgG and fibrinogen, increases in leakage of Evan's blue dye, decreases in levels of the tight junction proteins occludin and ZO-1, increases in astrocytes activation and microglia density where IgG extravasation was present. Chronic ingestion of caffeine protects against high cholesterol diet-induced increases in disruptions of the BBB, and caffeine and drugs similar to caffeine might be useful in the treatment of Alzheimer's disease

Diagrammatic approach to coherent backscattering of laser light by cold atoms: Double scattering revisited

We present a diagrammatic derivation of the coherent backscattering spectrum from two two-level atoms using the pump-probe approach, wherein the multiple scattering signal is deduced from single-atom responses, and provide a physical interpretation of the single-atom building blocks.Comment: 16 pages, 7 figure

Critique of a Pion Exchange Model for Interquark Forces

I describe four serious defects of a widely discussed pion exchange model for interquark forces: it doesn't solve the "spin-orbit problem" as advertised, it fails to describe the internal structure of baryon resonances, it leads to disastrous conclusions when extended to mesons, and it is not reasonably connected to the physics of heavy-light systems.Comment: 20 pages, 6 figures; some clarifications and references adde

Hadronic freeze-out following a first order hadronization phase transition in ultrarelativistic heavy-ion collisions

We analyze the hadronic freeze-out in ultra-relativistic heavy ion collisions at RHIC in a transport approach which combines hydrodynamics for the early, dense, deconfined stage of the reaction with a microscopic non-equilibrium model for the later hadronic stage at which the hydrodynamic equilibrium assumptions are not valid. With this ansatz we are able to self-consistently calculate the freeze-out of the system and determine space-time hypersurfaces for individual hadron species. The space-time domains of the freeze-out for several hadron species are found to be actually four-dimensional, and differ drastically for the individual hadrons species. Freeze-out radii distributions are similar in width for most hadron species, even though the Omega-baryon is found to be emitted rather close to the phase boundary and shows the smallest freeze-out radii and times among all baryon species. The total lifetime of the system does not change by more than 10% when going from SPS to RHIC energies.Comment: 11 pages, 4 eps-figures included, revised versio