On a Generalized Fifth-Order Integrable Evolution Equation and its Hierarchy

A general form of the fifth-order nonlinear evolution equation is considered. Helmholtz solution of the inverse variational problem is used to derive conditions under which this equation admits an analytic representation. A Lennard type recursion operator is then employed to construct a hierarchy of Lagrangian equations. It is explicitly demonstrated that the constructed system of equations has a Lax representation and two compatible Hamiltonian structures. The homogeneous balance method is used to derive analytic soliton solutions of the third- and fifth-order equations.Comment: 16 pages, 1 figur

Bright solitons in asymmetrically trapped Bose-Einstein condensate

We study the dynamics of bright solitons in a Bose-Einstein condensate (BEC) confined in a highly asymmetric trap. While working within the f ramework of a variational approach we carry out the stability analysis o f BEC solitons against collapse. When the number of atoms in the soliton exceeds a critical number $N_c$, it undergoes the so called primary col lapse. We find an analytical expression for $N_c$ in terms of appropriat e experimental quantities that are used to produce and confine the conde nsate. We further demonstrate that, in the geometry of the problem consi dered, the width of the soliton varies inversely as the number of consti tuent atoms.Comment: 5 pages, 1 figure

Experimental Realization of Quantum-Resonance Ratchets

Quantum-resonance ratchets associated with the periodically kicked particle are experimentally realized for the first time. This is achieved by using a Bose-Einstein condensate exposed to a pulsed standing light wave and prepared in an initial state differing from the usual plane wave. Both the standing-wave potential and the initial state have a point symmetry around some center and the ratchet arises from the non-coincidence of the two centers. The dependence of the directed quantum transport on the quasimomentum is studied. A detailed theoretical analysis is used to explain the experimental results.Comment: Accepted for publication in Physical Review Letters (November 2007

Implications of surface noise for the motional coherence of trapped ions

Electric noise from metallic surfaces is a major obstacle towards quantum applications with trapped ions due to motional heating of the ions. Here, we discuss how the same noise source can also lead to pure dephasing of motional quantum states. The mechanism is particularly relevant at small ion-surface distances, thus imposing a new constraint on trap miniaturization. By means of a free induction decay experiment, we measure the dephasing time of the motion of a single ion trapped 50~$\mu$m above a Cu-Al surface. From the dephasing times we extract the integrated noise below the secular frequency of the ion. We find that none of the most commonly discussed surface noise models for ion traps describes both, the observed heating as well as the measured dephasing, satisfactorily. Thus, our measurements provide a benchmark for future models for the electric noise emitted by metallic surfaces.Comment: (5 pages, 4 figures

The Schrodinger equation with Hulthen potential plus ring-shaped potential

We present the solutions of the Schr$\ddot{o}$dinger equation with the Hulth$\acute{e}$n potential plus ring-shape potential for $\ell\neq 0$ states within the framework of an exponential approximation of the centrifugal potential.Solutions to the corresponding angular and radial equations are obtained in terms of special functions using the conventional Nikiforov-Uvarov method. The normalization constant for the Hulth$\acute{e}$n potential is also computed.Comment: Typed with LateX,12 Pages, Typos correcte

Multiagent cooperation for solving global optimization problems: an extendible framework with example cooperation strategies

This paper proposes the use of multiagent cooperation for solving global optimization problems through the introduction of a new multiagent environment, MANGO. The strength of the environment lays in itsflexible structure based on communicating software agents that attempt to solve a problem cooperatively. This structure allows the execution of a wide range of global optimization algorithms described as a set of interacting operations. At one extreme, MANGO welcomes an individual non-cooperating agent, which is basically the traditional way of solving a global optimization problem. At the other extreme, autonomous agents existing in the environment cooperate as they see fit during run time. We explain the development and communication tools provided in the environment as well as examples of agent realizations and cooperation scenarios. We also show how the multiagent structure is more effective than having a single nonlinear optimization algorithm with randomly selected initial points

Electronic Signatures in E-Healthcare: The Need for a Federal Standard

Healthcare, like many industries, is fast embracing the benefits of modern information technology ( IT ). The wide range of available publications on the use of IT in healthcare indicates that IT provides the promise of faster and more comprehensive information about all aspects of the healthcare delivery process, to all classes of its consumers - patients, doctors, nurses, insurance adjudicators, health inspectors, epidemiologists, and biostatisticians. But the drive towards electronic information in health care is not rooted merely in efficiency; more recently, significant emphasis has been placed on patient safety issues raised by the Institute of Medicine\u27s ( IOM ) year 2001 quality report on the subject. It is believed that the deficiencies indicated in that report can be substantially overcome by the use of IT in health care. However, to make this transition successful and complete, all aspects of health care delivery, information management, and business transactions, have to be logically migrated into the electronic world. This includes the function and use of the signature. The use of signatures in business contexts has traditionally provided two functions of legal significance: 1) evidence that can attribute documents to a particular party, and 2) indication of assent and intent that the documents have legal effect. In the recent decades, state and federal statutes have substantiated these functional attributes to digital or electronic signatures. Many of these statutes derive from model codes, such as the Uniform Electronic Transactions Act ( UETA ), that attempt to standardize use and technology surrounding electronic signatures. Subsequent sections will attempt to identify gaps in the standards which prevent true transaction portability. Lack of portability defeats one of the fundamental goals of health care IT solutions - improved efficiency. The discussion will end with a proposal for a uniform federal statutory scheme for standardized electronic signatures for health care

Prediction of anti-Alzheimer’s activity of flavonoids targeting acetylcholinesterase in silico

Introduction – Prenylated and pyrano-flavonoids of the genus Artocarpus J. R. Forster & G. Forster are well known for their acetylcholinesterase (AchE) inhibitory, anticholinergic, antiinflammatory, antimicrobial, antioxidant, antiproliferative and tyrosinase inhibitory activities. Some of these compounds have also been shown to be effective against Alzheimer’s disease. Objective – The aim of the in silico study was to establish protocols to predict the most effective flavonoid from prenylated and pyrano-flavonoid classes for AchE inhibition linking to the potential treatment of Alzheimer’s disease. Methodology – Three flavonoids isolated from Artocarpus anisophyllus Miq. were selected for the study. With these compounds, Lipinski filter, ADME/Tox screening, molecular docking and QSAR were performed in silico. In vitro activity was evaluated by bioactivity staining based on the Ellman’s method. Results – In the Lipinski filter and ADME/Tox screening, all test compounds produced positive results, but in the target fishing, only one flavonoid could successfully target AchE. Molecular docking was performed on this flavonoid, and this compound gained the score as -13.5762. From the QSAR analysis the IC50 was found to be 1659.59 nM. Again, 100 derivatives were generated from the parent compound and docking was performed. The derivative number 20 was the best scorer i.e., -31.6392 and IC50 was predicted as 6.025 nM. Conclusion – Results indicated that flavonoids could be efficient inhibitors of AchE and thus, could be useful in the management of Alzheimer’s disease