Lump-like Structures in Scalar-field Models

In this work we investigate the presence of lump-like solutions in models described by a single real scalar field. We take advantage of a procedure recently used to describe explicit analytical solutions and we study several distinct models, showing how the parameters can be used to control the specific features of the lump-like structures. The proposed models are of direct interest to the construction of q-balls, to induce tachyonic excitations and gravitating structures of nontopological profile on braneworld models with a single extra dimension, to map solitons in optical fibers, and to describe collective excitations in Bose-Einstein condensates.Comment: 7 pages, 11 figure

Uma Análise Comparativa De Parâmetros Do Doppler Transcraniano Adquiridos Durante A Colocação De Stent Carotídeo E Endarterectomia Carotídea Por Semieversão

Background: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) have both been proposed for treatment of critical atherosclerotic stenosis located at the carotid bifurcation. Monitoring of hyperintense microembolic signals (MES) by transcranial Doppler ultrasound (TCD) is considered a method of quality control, both in CEA and in CAS. Objective: To analyze temporal distribution of MES throughout both semi-eversion CEA and CAS procedures and to evaluate changes in mean velocity of blood flow through the ipsilateral middle cerebral artery (MCA). Method: Thirty-three procedures (17 CEA and 16 CAS) were prospectively monitored using TCD and the data were related to three different stages of surgery (pre-cerebral protection, during cerebral protection and post-cerebral protection). Chi-square, Mann-Whitney, ANOVA and contrast tests were used for statistical analysis. Results: The MES were uniformly distributed in the CEA group, but not in the CAS group (p = 0.208). The number of MES was higher in the CAS group in all stages. The average flow in the MCA was similarly lower in both groups during the protection stage. Conclusion: CEA provoked a lower incidence of MES per procedure than CAS in all stages. The behavior of the averages of the mean of blood flow through the MCA was similar in both groups. © 2016, Sociedade Brasileira de Angiologia e Cirurgia Vascular. All rights reserved.15319720

Solitons of two-component Bose-Einstein condensates modulated in space and time

In this paper we present soliton solutions of two coupled nonlinear Schodinger equations modulated in the bspace and time. The approach allows us to obatin solitons with large variety of solutions depending on the nonlinearity and the potential profiles. As examples we show three cases with soliton solution in such system, one of them with potential varying between repulsive and attractive behavior and the others with nonlinearity localized and delocalized, respectively.Comment: 18 pages, 8 figure

Alternative scheme to generate a supersinglet state of three-level atoms

In this paper we propose an alternative scheme to generate a supersinglet state of three three-level atoms via a single-mode of a cavity QED based on the two-photon transitions described by the 'full microscopical Hamiltonian approach'. In it, three three-level atoms prepared in suitable initial states are sequentially sent through the cavity originally prepared in its vacuum state. After an appropriate choice of the atom-cavity interaction times plus a field detection the state that describes the whole atom-field system is projected in the desired supersinglet state. The fidelity and success probability of the state as well as the practical feasibility of the scheme are discussed.Comment: 10 pages, 3 figures, 4 table

Conditional displacement operator for traveling fields

We show that the conditional displacement operator $\hat{U}_{CD}=\exp [\hat{b}^{\dagger}\hat{b}(\beta \hat{a}^{\dagger}-\beta ^{\ast}\hat{a})]$ acting upon an arbitrary state of traveling waves can be well approximated by the action of a Kerr medium placed between two beam splitters whose respective second ports are fed by highly excited coherent states. Applications to the generation of nonclassical states and measurement of Wigner function of arbitrary states are also considered

Hole burning in a nanomechanical resonator coupled to a Cooper pair box

We propose a scheme to create holes in the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success probability and the fidelity are calculated and compared with those obtained in the atom-field system via distinct schemes. As an application we show how to use the hole-burning scheme to prepare (low excited) Fock states.Comment: 7 pages, 10 figure

Essential oil from Ageratum fastigiatum reduces expression of the pro-inflammatory cytokine tumor necrosis factor-alpha in peripheral blood leukocytes subjected to in vitro stimulation with phorbol myristate acetate

AbstractAgeratum fastigiatum (Gardner) R.M. King & H. Rob., a member of the Asteraceae family popularly known in Brazil as “matapasto”, is indicated in folk medicine as anti-inflammatory and analgesic. Despite its popular use, little is known about its potential effect on the parameters involved in an inflammatory response. The objective of this study was to characterize the chemical composition of the essential oil from A. fastigiatum and to evaluate the frequency of tumor necrosis factor alpha and interferon gamma producing cells in peripheral blood lymphocytes stimulated with phorbol myristate acetate in the presence of essential oil from A. fastigiatum. Non-toxic concentrations of essential oil from A. fastigiatum were evaluated in cultures of peripheral blood leucocytes using the trypan blue exclusion assay by flow cytometry. GC–MS analysis revealed that the prevalent compounds identified in the essential oil from A. fastigiatum sample were α-pinene, limonene, trans-caryophyllene, α-humulene, caryophyllene oxide, 1,2-humulene-epoxide, 1,6-humulanodien-3-ol, and α-cadinol. Results showed that exposure to essential oil from A. fastigiatum at concentrations of 0.5×10−2 and 1×10−2μl/ml caused no alterations in leukocyte viability as compared to the control group. Both concentrations lowered the percentage of tumor necrosis factor alpha (+)-lymphocytes and neutrophils. There were no changes in the percentage of lymphocytes positive for the interferon gamma cytokine. Our results suggest that part of the anti-inflammatory activity attributed to A. fastigiatum may be due to the effect of some of its components in decreasing the number of cells that produce the pro-inflammatory cytokine tumor necrosis factor alpha

Controlling Statistical Properties of a Cooper Pair Box Interacting with a Nanomechanical Resonator

We investigate the quantum entropy, its power spectrum, and the excitation inversion of a Cooper pair box interacting with a nanomechanical resonator, the first initially prepared in its excited state, the second prepared in a "cat"-state. The method uses the Jaynes-Cummings model with damping, with different decay rates of the Cooper pair box and distinct detuning conditions, including time dependent detunings. Concerning the entropy, it is found that the time dependent detuning turns the entanglement more stable in comparison with previous results in literature. With respect to the Cooper pair box excitation inversion, while the presence of detuning destroys the its collapses and revivals, it is shown that with a convenient time dependent detuning one recovers such events in a nice way.Comment: 10 pages, 10 figure

New Lump-like Structures in Scalar-field Models

In this work we investigate lump-like solutions in models described by a single real scalar field. We start considering non-topological solutions with the usual lump-like form, and then we study other models, where the bell-shape profile may have varying amplitude and width, or develop a flat plateau at its top, or even induce a lump on top of another lump. We suggest possible applications where these exotic solutions might be used in several distinct branches of physics.Comment: REvTex4, twocolumn, 10 pages, 9 figures; new reference added, to appear in EPJ