42 research outputs found
Global Minimum Depth In Edwards-Anderson Model
In the literature the most frequently cited data are quite contradictory, and
there is no consensus on the global minimum value of 2D Edwards-Anderson (2D
EA) Ising model. By means of computer simulations, with the help of exact
polynomial Schraudolph-Kamenetsky algorithm, we examined the global minimum
depth in 2D EA-type models. We found a dependence of the global minimum depth
on the dimension of the problem N and obtained its asymptotic value in the
limit . We believe these evaluations can be further used for
examining the behavior of 2D Bayesian models often used in machine learning and
image processing.Comment: 10 pages, 4 figures, 2 tables, submitted to conference on Engineering
Applications of Neural Networks (EANN 2019
Beyond Gross-Pitaevskii Mean Field Theory
A large number of effects related to the phenomenon of Bose-Einstein
Condensation (BEC) can be understood in terms of lowest order mean field
theory, whereby the entire system is assumed to be condensed, with thermal and
quantum fluctuations completely ignored. Such a treatment leads to the
Gross-Pitaevskii Equation (GPE) used extensively throughout this book. Although
this theory works remarkably well for a broad range of experimental parameters,
a more complete treatment is required for understanding various experiments,
including experiments with solitons and vortices. Such treatments should
include the dynamical coupling of the condensate to the thermal cloud, the
effect of dimensionality, the role of quantum fluctuations, and should also
describe the critical regime, including the process of condensate formation.
The aim of this Chapter is to give a brief but insightful overview of various
recent theories, which extend beyond the GPE. To keep the discussion brief,
only the main notions and conclusions will be presented. This Chapter
generalizes the presentation of Chapter 1, by explicitly maintaining
fluctuations around the condensate order parameter. While the theoretical
arguments outlined here are generic, the emphasis is on approaches suitable for
describing single weakly-interacting atomic Bose gases in harmonic traps.
Interesting effects arising when condensates are trapped in double-well
potentials and optical lattices, as well as the cases of spinor condensates,
and atomic-molecular coupling, along with the modified or alternative theories
needed to describe them, will not be covered here.Comment: Review Article (19 Pages) - To appear in 'Emergent Nonlinear
Phenomena in Bose-Einstein Condensates: Theory and Experiment', Edited by
P.G. Kevrekidis, D.J. Frantzeskakis and R. Carretero-Gonzalez (Springer
Verlag
Accelerated Partial Breast Irradiation (APBI): A review of available techniques
Breast conservation therapy (BCT) is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified
Nonneuronal cholinergic system in human erythrocytes : biological role and cinical relevance
The original publication is available at www.springerlink.com© Springer Science+Business Media, LLC 2010Acetylcholine is well known in the medical
setting as one of the most exemplary neurotransmitters. Its ubiquity in nature otherwise suggests a theoretically
diverse spectrum of action and an extremely early appearance in the evolutionary process. In humans, acetylcholine
and its synthesizing enzyme, choline acetyltransferase, have been found in various nonneural tissues such as the epithelium, mesothelium, endothelium, muscle,
immune cells and blood cells. The widespread expression of nonneuronal acetylcholine is accompanied by the ubiquitous presence of acetylcholinesterase and nicotinic/muscarinic
receptors. Structural and functional dissimilarities are evident between the nonneuronal and neuronal cholinergic
systems. An increasing body of evidence
throughout the last few years has placed acetylcholine as a major cellular signaling molecule in many pathways. Furthermore,
numerous erythrocyte physiological events in the microcirculation are strongly regulated by acetylcholine.
Thus, it is time to revise our understanding of the role of vascular acetylcholine in humans. Its biological and pathobiological roles must be evaluated in more detail to
eventually achieve novel therapeutical targets. The present article reviews recent findings about nonneuronal acetylcholine
in red blood cells, with special regard to (1) red cell rheology, (2) plasma ion concentrations, (3) nitric oxide
intracellular translocation and metabolism and (4) band 3 protein phosphorylation