Universal and deterministic manipulation of the quantum state of harmonic oscillators: a route to unitary gates for Fock State qubits

We present a simple quantum circuit that allows for the universal and deterministic manipulation of the quantum state of confined harmonic oscillators. The scheme is based on the selective interactions of the referred oscillator with an auxiliary three-level system and a classical external driving source, and enables any unitary operations on Fock states, two-by-two. One circuit is equivalent to a single qubit unitary logical gate on Fock states qubits. Sequences of similar protocols allow for complete, deterministic and state-independent manipulation of the harmonic oscillator quantum state.Comment: 4 pages, 4 figure

Feasibility of approximating spatial and local entanglement in long-range interacting systems using the extended Hubbard model

We investigate the extended Hubbard model as an approximation to the local and spatial entanglement of a one-dimensional chain of nanostructures where the particles interact via a long range interaction represented by a `soft' Coulomb potential. In the process we design a protocol to calculate the particle-particle spatial entanglement for the Hubbard model and show that, in striking contrast with the loss of spatial degrees of freedom, the predictions are reasonably accurate. We also compare results for the local entanglement with previous results found using a contact interaction (PRA, 81 (2010) 052321) and show that while the extended Hubbard model recovers a better agreement with the entanglement of a long-range interacting system, there remain realistic parameter regions where it fails to predict the quantitative and qualitative behaviour of the entanglement in the nanostructure system.Comment: 6 pages, 5 figures and 1 table; added results with correlated hopping term; accepted by EP

Abrupt Changes in the Dynamics of Quantum Disentanglement

Entanglement evolution in high dimensional bipartite systems under dissipation is studied. Discontinuities for the time derivative of the lower bound of entanglement of formation is found depending on the initial conditions for entangled states. This abrupt changes along the evolution appears as precursors of entanglement sudden death.Comment: 4 pages and 6 figures, submitted for publicatio

Melatonin reduces the severity of experimental amoebiasis

<p>Abstract</p> <p>Background</p> <p>Melatonin has immunomodulatory effects but very little is known about its influence in protozoan infections, such as <it>Entamoeba histolytica</it>, which causes amoebiasis, a disease with significant morbidity and mortality. In this study, we evaluated the effects of exogenous melatonin interference in experimental amoebiasis and on interactions between human blood cells and <it>E. histolytica </it>trophozoites.</p> <p>Methods</p> <p>The effect of melatonin was investigated in models of experimental amoebiasis in hamsters and rats by evaluating the area of necrosis induced by <it>E. histolytica</it>. The activity of melatonin on the interactions between leukocytes and amoebae was determined by examining leukophagocytosis. For <it>in vitro </it>tests, polymorphonuclear and mononuclear human blood leucocytes were incubated with <it>E. histolytica </it>trophozoites.</p> <p>Results</p> <p>The areas of amoebic necrosis were significantly reduced in animals treated with melatonin. Melatonin treatment increased leukophagocytosis but was associated with a greater number of dead amoebae.</p> <p>Conclusions</p> <p>These results suggest that melatonin may play a beneficial role in the control of amoebic lesions, raising the possibility that this drug may be used as an adjuvant in anti-amoebic therapy.</p

FLOW IN POROUS ELEMENTS: A THEORETICAL AND EXPERIMENTAL ANALYSIS OF THE EFFECTS OF THE CAPILLARY EFFORTS CAUSED BY WATER PERCOLATION IN MASONRY POROUS ELEMENTS

The identification of cracks in masonry bricks is quite common, not only after the edification but also during the process. Moistness absorbed by the elements of the wall (bricks and mortar) is one those factors. This moistness comes from the air, rain, soil absorption and even the excess of water in the laying mortar. In contact with the wall porous elements, the moistness will contribute to the capillary percolation, giving berth to considerable internal efforts which will induce the presence of cracks. This study leads to an analysis for the obtainment of fluid pressure and velocity medium values, measuring the deformation of the elements. The paper brings the equating to predict and estimate the velocities and efforts medium values in the ceramics elements. The flow in porous elements is studied and a proposal of modelingto estimate Velocities and Efforts values is presented