Quantum behaviour of open pumped and damped Bose-Hubbard trimers

We propose and analyse analogs of optical cavities for atoms using three-well inline Bose-Hubbard models with pumping and losses. With one well pumped and one damped, we find that both the mean-field dynamics and the quantum statistics show a qualitative dependence on the choice of damped well. The systems we analyse remain far from equilibrium, although most do enter a steady-state regime. We find quadrature squeezing, bipartite and tripartite inseparability and entanglement, and states exhibiting the EPR paradox, depending on the parameter regimes. We also discover situations where the mean-field solutions of our models are noticeably different from the quantum solutions for the mean fields. Due to recent experimental advances, it should be possible to demonstrate the effects we predict and investigate in this article.Comment: 20 pages, 8 figures, theoretica

Mapping the train model for earthquakes onto the stochastic sandpile model

We perform a computational study of a variant of the ``train'' model for earthquakes [PRA 46, 6288 (1992)], where we assume a static friction that is a stochastic function of position rather than being velocity dependent. The model consists of an array of blocks coupled by springs, with the forces between neighbouring blocks balanced by static friction. We calculate the probability, P(s), of the occurrence of avalanches with a size s or greater, finding that our results are consistent with the phenomenology and also with previous models which exhibit a power law over a wide range. We show that the train model may be mapped onto a stochastic sandpile model and study a variant of the latter for non-spherical grains. We show that, in this case, the model has critical behaviour only for grains with large aspect ratio, as was already shown in experiments with real ricepiles. We also demonstrate a way to introduce randomness in a physically motivated manner into the model.Comment: 14 pages and 6 figures. Accepted in European Physical Journal

Ultracold atomic mode splitter for the entanglement of separated atomic samples

We propose and analyze the use of a three-well Bose-Hubbard model for the creation of two spatially separated entangled atomic samples. Our three wells are in a linear configuration, with all atoms initially in the middle well, which gives some spatial separation of the two end wells. The evolution from the initial quantum state allows for the development of entanglement between the atomic modes in the two end wells. We show how the detected entanglement and the well occupations are time dependent. We propose a method for preserving the en-tanglement by turning off the different interactions when it reaches its first maximum. We analyze the system with both Fock and coherent initial states, showing that the violations of the chosen inequality exist only for initial Fock states and that the collisional nonlinearity degrades them. This system is a preliminary step towards producing entangled atomic samples that can be spatially separated using recently developed methods of potential manipulation and thus help close the locality loophole in tests of quantum mechanics

Quantum correlations in pumped and damped Bose-Hubbard dimers

We propose and analyze two-well Bose-Hubbard models with pumping and losses, finding that these models, with damping and loss able to be added independently to each well, offer a flexibility not found in optical coupled cavity systems. With one well pumped, we find that both the mean-field dynamics and the quantum statistics show a quantitative dependence on the choice of damped well. Both the systems we analyze remain far from equilibrium, preserving good coherence between the wells in the steady state. We find a degree of quadrature squeezing and mode entanglement in these systems. Due to recent experimental advances, it should be possible to demonstrate the effects we investigate and predict

Diagnósticos de Enfermería en pacientes post-cateterismocardiaco - contribuición de Orem

Estudo de múltiplos casos, transversal, envolvendo 30 clientes, no período pós-cateterismo cardíaco. Objetivou estabelecer Diagnósticos de Enfermagem da North American Nursing Diagnosis Association (NANDA). O método de coleta de dados foi o Processo de Enfermagem fundamentado na Teoria Déficit do Auto cuidado. Foram estabelecidos 25 diferentes Diagnósticos de Enfermagem. Todos os pacientes apresentaram Integridade tissular prejudicada; Risco para infecção; Dor aguda (região inguinal); Mobilidade física prejudicada, Déficit do auto cuidado para higiene íntima e Risco para lesão orgânica renal. Conclui-se que a Teoria do Déficit de auto cuidado facilitou a classificação de Diagnósticos de Enfermagem da NANDA, contribuindo para individualização, humanização e qualificação da assistência de enfermagem, além de promover o auto-conhecimento, auto-controle e a participação dos clientes no próprio cuidado. ________________________________________________________________________________________ ABSTRACTSectional study of multiple cases involving 30 patients after heart catheterization aiming to establish the nursing diagnoses according to the North American Nursing Diagnoses Association (NANDA). The method of data collection was the Nursing Process based on the Self-care Deficit Theory. Twenty- five different nursing diagnoses had been established. All patients presented Impaired tissue integrity, Risk of infection, Pain incisive in the area inguinal, Injured physical mobility, Self-care deficit related to personal hygiene, and Risk of organic renal lesion. It has been concluded that the Self-care Deficit theory allowed the classification of all nursing diagnoses according to NANDA. It contributed to the nursing assistance individualization, humanization, and qualification. Beyond advance self-knowledge, self-control and patient participation on his/her self-car. ________________________________________________________________________________________ RESUMENEstudio transversal de múltiplos casos, incluyendo 30 pacientes, en período post-cateterismo cardíaco. Con elobjectivo de establecer Diagnósticos de Enfermería de North American Nursing Diagnosis Association (NANDA-Asociación Norteamericana de Diagnósticos de Enfermería).El método de recolecta de datos fue el Proceso deEnfermería, fundamentado en la Teoría de Déficit del Autocuidado de Dorothea Orem. Fueron establecidos 25diferentes Diagnósticos de Enfermería. Todos los pacientes presentaron perfusión tisular perjudicada; Riesgopara infección; Dolor aguda em la región ingle, Movilidad física prejudicada. Déficit de autocuidado para higieneíntima y riesgo para lesión orgánica renal fue identificado en 100% de los pacientes. Se concluye que, la Teoríade Déficit de Autocuidado de Dorothea Orem, facilitó la clasificación de Diagnósticos de Enfermería de NANDA.Contribuyó para individualización, humanización y calificación de la asistencia de enfermería, incentivando laparticipación del paciente en el propio cuidado, en las cuestiones de autoconocimiento y autocontrol de lasalud

Baroreflex function in conscious rats submitted to iron overload

Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv) was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold), in contrast to the TIO group (2-fold). Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively). The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg) 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity.Universidade Federal de Ouro Preto NUPEB Departamento de Ciências BiológicasUniversidade Federal de Ouro Preto Escola de Nutrição Departamento de AlimentosUniversidade Federal de Minas Gerais Instituto de Ciências Biológicas Departamento de Fisiologia e BiofísicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUNIFESP, EPM, Depto. de FisiologiaSciEL

Fragmentation Experiment and Model for Falling Mercury Drops

The experiment consists of counting and measuring the size of the many fragments observed after the fall of a mercury drop on the floor. The size distribution follows a power-law for large enough fragments. We address the question of a possible crossover to a second, different power-law for small enough fragments. Two series of experiments were performed. The first uses a traditional film photographic camera, and the picture is later treated on a computer in order to count the fragments and classify them according to their sizes. The second uses a modern digital camera. The first approach has the advantage of a better resolution for small fragment sizes. The second, although with a poorer size resolution, is more reliable concerning the counting of all fragments up to its resolution limit. Both together clearly indicate the real existence of the quoted crossover. The model treats the system microscopically during the tiny time interval when the initial drop collides with the floor. The drop is modelled by a connected cluster of Ising spins pointing up (mercury) surrounded by Ising spins pointing down (air). The Ising coupling which tends to keep the spins segregated represents the surface tension. Initially the cluster carries an extra energy equally shared among all its spins, corresponding to the coherent kinetic energy due to the fall. Each spin which touches the floor loses its extra energy transformed into a thermal, incoherent energy represented by a temperature used then to follow the dynamics through Monte Carlo simulations. Whenever a small piece becomes disconnected from the big cluster, it is considered a fragment, and counted. The results also indicate the existence of the quoted crossover in the fragment-size distribution.Comment: 6 pages, 3 figure