811 research outputs found

    Long-distance distribution of genuine energy-time entanglement

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    Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell's inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibers that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fiber-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibers.Comment: 6 pages, 3 figures. Matches published versio

    A higher quantum bound for the V\'ertesi-Bene-Bell-inequality and the role of POVMs regarding its threshold detection efficiency

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    Recently, V\'{e}rtesi and Bene [Phys. Rev. A. {\bf 82}, 062115 (2010)] derived a two-qubit Bell inequality, ICH3I_{CH3}, which they show to be maximally violated only when more general positive operator valued measures (POVMs) are used instead of the usual von Neumann measurements. Here we consider a general parametrization for the three-element-POVM involved in the Bell test and obtain a higher quantum bound for the ICH3I_{CH3}-inequality. With a higher quantum bound for ICH3I_{CH3}, we investigate if there is an experimental setup that can be used for observing that POVMs give higher violations in Bell tests based on this inequality. We analyze the maximum errors supported by the inequality to identify a source of entangled photons that can be used for the test. Then, we study if POVMs are also relevant in the more realistic case that partially entangled states are used in the experiment. Finally, we investigate which are the required efficiencies of the ICH3I_{CH3}-inequality, and the type of measurements involved, for closing the detection loophole. We obtain that POVMs allow for the lowest threshold detection efficiency, and that it is comparable to the minimal (in the case of two-qubits) required detection efficiency of the Clauser-Horne-Bell-inequality.Comment: 11 Pages, 16 Figure

    Prostatic carcinomas with neuroendocrine differentiation diagnosed in needle biopsies, a morphologic study of 7 cases among 465 sequential biopsies in a tertiary cancer center

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    Purpose: Neuroendocrine carcinomas (NEC) of the prostate are rare, with only a few series hitherto reported. the objective of this study was to assess in a single institution the clinical and morphologic characteristics of neuroendocrine carcinomas diagnosed in needle core biopsies.Materials and Methods: the current study analyses seven cases diagnosed in needle biopsies at a large tertiary regional cancer center from Northeastern Brazil. Two pathologists reviewed specimens retrospectively, and demographic and morphologic characteristics were compared to 458 acinar tumors diagnosed in the same period.Results: There were five small cell carcinomas and two low-grade neuroendocrine carcinomas (carcinoid). NEC were associated with an acinar component in 5/7 cases and the Gleason score of the acinar component was always > 6. the number of cores involved in prostates with NEC was greater (65% compared to 24% of acinar tumors, p < 0.05). the mean PSA at diagnosis was 417.7 (range 5.7-1593, SD 218.3), compared to 100.5 (p = 0.1) of acinar tumors (range 0.3-8545, SD 22.7). Prostates harboring NEC were bigger (p < 0.001, mean volume 240 mL vs. 53 mL of acinar tumors). Treatment of NEC included palliative surgery, chemotherapy, and hormonal therapy.Conclusions: NEC of the prostate is rare and often associated with a high-grade acinar component. Prostates with NEC tend to be larger and involve a greater number of cores than acinar tumors. PSA at diagnosis does not seem to predict the presence of NE tumors in needle biopsy.Hosp Canc, Inst Canc Ceara, BR-60430230 Fortaleza, Ceara, BrazilEscola Paulista Med, BR-04023 São Paulo, BrazilEscola Paulista Med, BR-04023 São Paulo, BrazilWeb of Scienc

    A tale of shells and claws: the signal crayfish as a threat to the pearl mussel Margaritifera margaritifera in Europe

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    The freshwater pearl mussel Margaritifera margaritifera is a highly threatened species in Europe. Several mechanisms may be responsible for the decline in distribution and abundance of European pearl mussel populations, but almost no quantitative data exists about the possible negative impacts of invasive alien species (IAS). In this study, we clearly demonstrate that the invasive signal crayfish Pacifastacus leniusculus predates pearl mussels, using a laboratorial experiment followed by in situ validation in four rivers in the North of Portugal (Mente, Rabacal, Tuela and Baceiro Rivers; Douro Basin). In the laboratory, the crayfish had a clear preference for small-sized pearl mussels but no differences in predation were found in mesocosms with and without sediment. In addition, we clearly demonstrated that the signal crayfish predates pearl mussels in natural conditions and detected a significant density dependent effect (i.e., sites with more crayfish presented higher number of pearl mussel shells with marks of predation). Given the recent introduction of the signal crayfish and the potential negative impacts on pearl mussel populations we also investigated its autoecology (distribution, abundance, size structure and sex-ratio) in the four studied rivers. Significant differences in average abundance and size of the crayfish were detected between sites and the sex-ratio was highly skewed to females. In view of the widespread distribution of signal crayfish (and other invasive crayfish species) in Europe, future management actions devoted to the conservation of pearl mussels should take in consideration the possible negative effects of these predators, especially on juveniles.This work was supported by: i) POSEUR (15-2018-03) and ICNF funds under project CP01-MARG-QUERCUS/2018 and ii) European Investment Funds by FEDER/COMPETE/POCI -Operational Competitiveness and Internationalization Program, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT -Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013. FCT also support MLL with a doctoral grant (SFRH/BD/115728/2016). We thank the four anonymous reviewers for the suggestions made, which significantly improved the clarity of the manuscript

    Energetic characterization of Matá-Matá wood from the brazilian rainforest (Eschweilera Mart Ex Dc).

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    Apesar da grande diversidade da Floresta Amazônica, apenas um número restrito de espécies arbóreas é explorado, resultando em um aproveitamento parcial das áreas florestais em exploração, com conseqüências técnicas, econômicas e ambientais desvantajosas. Muitas espécies de grande freqüência na Amazônia brasileira, aptas ao manejo florestal, algumas vezes não são comercializadas por desconhecimento de suas propriedades, entre estas, cita-se o gênero Eschweilera Mart. Ex DC. ? Lecythidaceae, popularmente conhecido como matá-matá. Tendo isto em vista, o presente trabalho objetivou caracterizar física e quimicamente, e avaliar o potencial energético da madeira de Eschweilera. Para tanto, determinou-se os teores dos principais componentes químicos, poder calorífico superior (PCS), densidade básica (DB) e a densidade energética (DE) da madeira de 11 indivíduos de matá-matá. Os resultados observados foram comparados com os obtidos a partir de um clone de Eucalyptus comumente utilizado como fonte energética. As madeiras de Eschweilera sp., comparativamente ao Eucalyptus, apresentaram maiores valores de DB, DE, teor em lignina e minerais. A madeira de matá-matá apresenta características químicas e física superiores às espécies comumente utilizadas como fonte de energia

    Determinação do fluxo de múltiplos marcadores de digesta em carneiros utilizando técnicas alternativas de análise.

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    Um experimento foi desenvolvido para avaliar a utilização de técnicas analíticas alternativas na determinação da taxa de passagem ruminal (turnover) de diferentes marcadores de digesta em carneiros deslanados na raça Santa Inês

    Performance and digestive characteristics in dairy cattle maintained under grazing regime and supplemented with linseed.

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    Linseed is characterized by the rich unsaturated fatty acids and slow release of oil in the rumen. The objective of the present study was to evaluate the intake, rumen degradability, and digestibility of dairy cattle maintained under grazing regime and supplemented with linseed. Twelve Girolando (¾ Holstein × ¼ Gir) cows with a mean age of 5.2 ± 1.9 years and body weight of 583.9 ± 67.6 kg were used. The cows were maintained in a rotational grazing system on the mombaça grass (Panicum maximum) and divided into 2 experimental groups. The CONTR (n = 6) group received only the base diet (pasture) and the LINS group (n = 6) received pasture plus linseed. Initially, a fifteen-day adaptation period was established to stabilize the desired consumption amount. After this period, the animals received 800 g of linseed for 126 d. The ruminal degradability was evaluated using 2 males with a cannula in the rumen, and they were provided the same experimental diet. The measured dry matter production of pasture did not show differences during the experimental period. The intake of crude protein and ethereal extract was higher, whereas neutral detergent fiber content was lower in the cows supplemented with linseed. However, this did not alter the weight gain and digestibility coefficients, except the digestibility coefficient of the ethereal extract. At the ruminal level, linseed showed low effective and potential degradability with negative effect on grass degradability.Título em português: Desempenho e características digestivas em bovinos leiteiros mantidos em regime de pastoreio suplementados com linhaça

    Use of fuzzy systems to support decision making in the choice of reproductive bulls.

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    This work presents where a fuzzy rule-based system was constructed in order to offer support to the evaluation of reproductive bulls.1 pôster. IMAS. Pôster #45312

    Use of fuzzy systems to support decision making in the choice of reproductive bulls.

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    This work presents a case study where a fuzzy rule-based system was constructed in order to offer support to the evaluation of reproductive bulls.IMAS. Pôster #45312
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