769 research outputs found

    Frequency noise and intensity noise of next-generation gravitational-wave detectors with RF/DC readout schemes

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    The sensitivity of next-generation gravitational-wave detectors such as Advanced LIGO and LCGT should be limited mostly by quantum noise with an expected technical progress to reduce seismic noise and thermal noise. Those detectors will employ the optical configuration of resonant-sideband-extraction that can be realized with a signal-recycling mirror added to the Fabry-Perot Michelson interferometer. While this configuration can reduce quantum noise of the detector, it can possibly increase laser frequency noise and intensity noise. The analysis of laser noise in the interferometer with the conventional configuration has been done in several papers, and we shall extend the analysis to the resonant-sideband-extraction configuration with the radiation pressure effect included. We shall also refer to laser noise in the case we employ the so-called DC readout scheme.Comment: An error in Fig. 10 in the published version in PRD has been corrected in this version; an erratum has been submitted to PRD. After correction, this figure reflects a significant difference in the ways RF and DC readout schemes are susceptible to laser noise. In addition, the levels of mirror loss imbalances and input laser amplitude noise have also been updated to be more realistic for Advanced LIG

    The chain rule implies Tsirelson's bound: an approach from generalized mutual information

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    In order to analyze an information theoretical derivation of Tsirelson's bound based on information causality, we introduce a generalized mutual information (GMI), defined as the optimal coding rate of a channel with classical inputs and general probabilistic outputs. In the case where the outputs are quantum, the GMI coincides with the quantum mutual information. In general, the GMI does not necessarily satisfy the chain rule. We prove that Tsirelson's bound can be derived by imposing the chain rule on the GMI. We formulate a principle, which we call the no-supersignalling condition, which states that the assistance of nonlocal correlations does not increase the capability of classical communication. We prove that this condition is equivalent to the no-signalling condition. As a result, we show that Tsirelson's bound is implied by the nonpositivity of the quantitative difference between information causality and no-supersignalling.Comment: 23 pages, 8 figures, Added Section 2 and Appendix B, result unchanged, Added reference

    Blood and tissue biomarker analysis in dogs with osteosarcoma treated with palliative radiation and intra-tumoral autologous natural killer cell transfer.

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    We have previously reported radiation-induced sensitization of canine osteosarcoma (OSA) to natural killer (NK) therapy, including results from a first-in-dog clinical trial. Here, we report correlative analyses of blood and tissue specimens for signals of immune activation in trial subjects. Among 10 dogs treated with palliative radiotherapy (RT) and intra-tumoral adoptive NK transfer, we performed ELISA on serum cytokines, flow cytometry for immune phenotype of PBMCs, and PCR on tumor tissue for immune-related gene expression. We then queried The Cancer Genome Atlas (TCGA) to evaluate the association of cytotoxic/immune-related gene expression with human sarcoma survival. Updated survival analysis revealed five 6-month survivors, including one dog who lived 17.9 months. Using feeder line co-culture for NK expansion, we observed maximal activation of dog NK cells on day 17-19 post isolation with near 100% expression of granzyme B and NKp46 and high cytotoxic function in the injected NK product. Among dogs on trial, we observed a trend for higher baseline serum IL-6 to predict worse lung metastasis-free and overall survival (P = 0.08). PCR analysis revealed low absolute gene expression of CD3, CD8, and NKG2D in untreated OSA. Among treated dogs, there was marked heterogeneity in the expression of immune-related genes pre- and post-treatment, but increases in CD3 and CD8 gene expression were higher among dogs that lived > 6 months compared to those who did not. Analysis of the TCGA confirmed significant differences in survival among human sarcoma patients with high and low expression of genes associated with greater immune activation and cytotoxicity (CD3e, CD8a, IFN-γ, perforin, and CD122/IL-2 receptor beta). Updated results from a first-in-dog clinical trial of palliative RT and autologous NK cell immunotherapy for OSA illustrate the translational relevance of companion dogs for novel cancer therapies. Similar to human studies, analyses of immune markers from canine serum, PBMCs, and tumor tissue are feasible and provide insight into potential biomarkers of response and resistance

    Cooling of a mirror by radiation pressure

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    We describe an experiment in which a mirror is cooled by the radiation pressure of light. A high-finesse optical cavity with a mirror coated on a mechanical resonator is used as an optomechanical sensor of the Brownian motion of the mirror. A feedback mechanism controls this motion via the radiation pressure of a laser beam reflected on the mirror. We have observed either a cooling or a heating of the mirror, depending on the gain of the feedback loop.Comment: 4 pages, 6 figures, RevTe

    Parametric instabilities in magnetized multicomponent plasmas

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    This paper investigates the excitation of various natural modes in a magnetized bi-ion or dusty plasma. The excitation is provided by parametrically pumping the magnetic field. Here two ion-like species are allowed to be fully mobile. This generalizes our previous work where the second heavy species was taken to be stationary. Their collection of charge from the background neutral plasma modifies the dispersion properties of the pump and excited waves. The introduction of an extra mobile species adds extra modes to both these types of waves. We firstly investigate the pump wave in detail, in the case where the background magnetic field is perpendicular to the direction of propagation of the pump wave. Then we derive the dispersion equation relating the pump to the excited wave for modes propagating parallel to the background magnetic field. It is found that there are a total of twelve resonant interactions allowed, whose various growth rates are calculated and discussed.Comment: Published in May 2004; this is a late submission to the archive. 14 pages, 8 figure

    Avaliação ambiental no processo de implantação na produção integrada de pêssegos nos municípios de Araucária e Lapa - Paraná: um estudo de caso.

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    Nas últimas décadas vem, sendo evidenciado um maior reconhecimento das questões ambientais relacionadas com a produção agrícola. No sentido de contribuir com essa tendência, o presente trabalho apresenta resultados de avaliações ambientais da adoção da Produção Integrada de Pêssego (PIP) em dois estabelecimentos rurais, nos municípios de Araucária e LapaIPR. O aplicativo empregado (Ambitec-Agro) analisa o desempenho ambiental de uma determinada tecnologia de produção, como a PI, em relação a um sistema de produção tradicionalmente utilizado. O resultado da avaliação apontou que o índice de impacto ambiental, que pode variar de -15 a + 15, foi de +3,66 pontos com a adoção da PIP no pomar em Araucária, e de +3,13 pontos no pomar em Lapa. O presente estudo revela que a exploração do pêssego no sistema PIP, quando comparada com o cultivo convencional, traz impactos positivos ao meio ambiente, sendo os indicadores, relacionados à redução no uso de agrotóxicos, à biodiversidade, à qualidade do solo e ao uso de recursos naturais, que registraram valores positivos mais expressivos

    Diagonal-unitary 2-designs and their implementations by quantum circuits

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    We study efficient generations of random diagonal-unitary matrices, an ensemble of unitary matrices diagonal in a given basis with randomly distributed phases for their eigenvalues. Despite the simple algebraic structure, they cannot be achieved by quantum circuits composed of a few-qubit diagonal gates. We introduce diagonal-unitary tt-designs and present two quantum circuits that implement diagonal-unitary 22-designs with the computational basis in NN-qubit systems. One is composed of single-qubit diagonal gates and controlled-phase gates with randomized phases, which achieves an exact diagonal-unitary 22-design after applying the gates on all pairs of qubits. The number of required gates is N(N1)/2N(N-1)/2. If the controlled-Z gates are used instead of the controlled-phase gates, the circuit cannot achieve an exact 22-design, but achieves an ϵ\epsilon-approximate 22-design by applying gates on randomly selected pairs of qubits. Due to the random choice of pairs, the circuit obtains extra randomness and the required number of gates is at most O(N2(N+log1/ϵ))O(N^2(N+\log1/\epsilon)). We also provide an application of the circuits, a protocol of generating an exact 22-design of random states by combining the circuits with a simple classical procedure requiring O(N)O(N) random classical bits.Comment: Revised, 22 pages + Appendix, 3 figures; major revision from v2; presentation is improved in v4; v5 is a published versio

    The maximally entangled symmetric state in terms of the geometric measure

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    The geometric measure of entanglement is investigated for permutation symmetric pure states of multipartite qubit systems, in particular the question of maximum entanglement. This is done with the help of the Majorana representation, which maps an n qubit symmetric state to n points on the unit sphere. It is shown how symmetries of the point distribution can be exploited to simplify the calculation of entanglement and also help find the maximally entangled symmetric state. Using a combination of analytical and numerical results, the most entangled symmetric states for up to 12 qubits are explored and discussed. The optimization problem on the sphere presented here is then compared with two classical optimization problems on the S^2 sphere, namely Toth's problem and Thomson's problem, and it is observed that, in general, they are different problems.Comment: 18 pages, 15 figures, small corrections and additions to contents and reference

    Neonectria ditissima physiological traits and susceptibility of "Gala" and "Eva" detached apple fruit.

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    European Canker and Neonectria fruit rot (NFR), caused by Neonectria ditissima, has become a major problem for the production of apples (Malus domestica) in Brazil. This study characterized environmental factors affecting in vitro growth and germination of Neonectria ditissima as well as infection, colonization and reproduction, ex vivo, on ?Gala? and ?Eva? fruit. Temperatures between 17 to 20 °C were optimum for mycelial growth, and minimal growth occurred at 35 °C. Micro/macroconidia sporulation ratio was lower at 10 °C for most of the isolates tested, and no macroconidia were produced at 30 °C. More than 70% of conidia germinated after 12 h of exposure to constant humidity incubation and a temperature of 25 °C. Germination rate as high as 90% occurred after 48 h regardless of the temperature. Incubation of 2 h with high humidity is not sufficient for germination of 10% of conidia at any temperature between 10 to 30 °C. The cultivars Eva and Gala did not differ in relation to incubation period. A minimum of 25 days was necessary for sporulation on fruit incubated at 16.8?21.7 °C. Unwounded fruit did not present symptoms even 40 days after inoculation on intact epidermis, demonstrating the need of wounds for NFR development. Keywords Cylindrocarpon heteronema . Malus domestica . Nectria galligena . Basic biology . Postharvest diseas
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