122 research outputs found

    Continuous variable quantum teleportation with sculptured and noisy non-Gaussian resources

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    We investigate continuous variable (CV) quantum teleportation using relevant classes of non-Gaussian states of the radiation field as entangled resources. First, we introduce the class two-mode squeezed symmetric superposition of Fock states, including finite truncations of twin-beam Gaussian states as special realizations. These states depend on a set of free independent parameters that can be adjusted for the optimization of teleportation protocols, with an enhancement of the success probability of teleportation both for coherent and Fock input states. We show that the optimization procedure reduces the entangled resources to truncated twin beam states, which thus represents an optimal class of non-Gaussian resources for quantum teleportation. We then introduce a further class of two-mode non-Gaussian entangled resources, in the form of squeezed cat-like states. We analyze the performance and the properties of such states when optimized for (CV) teleportation, and compare them to the optimized squeezed Bell-like states introduced in a previous work \cite{CVTelepNoi}. We discuss how optimal resources for teleportation are characterized by a suitable balance of entanglement content and squeezed vacuum affinity. We finally investigate the effects of thermal noise on the efficiency of quantum teleportation. To this aim, a convenient framework is to describe noisy entangled resources as linear superpositions of non-Gaussian state and thermal states. Although the presence of the thermal component strongly reduces the teleportation fidelity, noisy non-Gaussian states remain preferred resources when compared to noisy twin-beam Gaussian states.Comment: 11 pages, 8 figures. Largely revised and expanded version. New material and sections added. To appear in EPJ-ST (Proceedings of the Central European Workshop on Quantum Optics 2007. 14th Edition, 1-5 June 2007, Palermo, Italy

    Tunable non-Gaussian resources for continuous-variable quantum technologies

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    We introduce and discuss a set of tunable two-mode states of continuous-variable systems, as well as an efficient scheme for their experimental generation. This novel class of tunable entangled resources is defined by a general ansatz depending on two experimentally adjustable parameters. It is very ample and flexible as it encompasses Gaussian as well as non-Gaussian states. The latter include, among others, known states such as squeezed number states and de-Gaussified photon-added and photon-subtracted squeezed states, the latter being the most efficient non-Gaussian resources currently available in the laboratory. Moreover, it contains the classes of squeezed Bell states and even more general non-Gaussian resources that can be optimized according to the specific quantum technological task that needs to be realized. The proposed experimental scheme exploits linear optical operations and photon detections performed on a pair of uncorrelated two--mode Gaussian squeezed states. The desired non-Gaussian state is then realized via ancillary squeezing and conditioning. Two independent, freely tunable experimental parameters can be exploited to generate different states and to optimize the performance in implementing a given quantum protocol. As a concrete instance, we analyze in detail the performance of different states considered as resources for the realization of quantum teleportation in realistic conditions. For the fidelity of teleportation of an unknown coherent state, we show that the resources associated to the optimized parameters outperform, in a significant range of experimental values, both Gaussian twin beams and photon-subtracted squeezed states.Comment: 13 pages, 7 figure

    Cross-cultural adaptation, validity and reliability study of the italian version of the back pain functional scale

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    SUMMARY Introduction. The Back Pain Functional Scale is a scale to assess disability in Low Back Pain patients. The purpose of this study was to translate, culturally adapt and validate the BPFS from the original English language into Italian. Materials and methods. Translation and cultural adaptation have been performed following international guidelines. 170 italian-speaking subjects with low back pain were recruited; 58 of them also performed the re-test. Internal consistency was assessed by calculating Cronbach’s Alpha and test-retest reliability was assessed by calculat ing the Intraclass Correlation Coefficient (ICC). Exploratory factor analysis and was performed to assess the construct validity and the correlation with other clinical scales was observed through Pearson’s correlation coefficients. Results. High internal consistency (Cronbach’s Alpha = 0.912) and very good test-re test reliability (ICC = 0.956) were found. Pearson’s correlation coefficient showed statistically significant correlations (p < 0.01) with the BPFS, FRI and ODI. Conclusions. The Italian version of the BPFS showed with good reliability and construct validity. This scale can be considered for the assessment of functional disabil ity in subjects with LBP: short, intuitive and easy to understand. It can certainly be used for both clinical practice and research

    Letteratura e prospettive emergenti sul rapporto fra innovazione e competizione fra imprese

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    L'obiettivo del lavoro è di identificare e argomentare i contributi più significativi pubblicati nelle riviste Research Policy e European Journal of Innovation Management, rilevanti ai fini di una interpretazione del rapporto tra innovazione e competitività. Alcuni principali temi emersi dallo studio sono: 1) l'evoluzione da innovazione di prodotto a innovazione di mercato; 2) i requisiti per l'implementazione dell'innovazione; 3) i fenomeni di "conservazione" nell'impresa; 4) l'innovazione come "solution provider"; 5) "solution innovation" come nuovo paradigma per la competitività; 6) gli orientamenti all'innovazione. L'analisi dei contributi permette di individuare alcune interessanti ambiti per future ricerche

    Genome sequence of an alkaliphilus species isolated from historically contaminated sediments of the gulf of Naples (Mediterranean Sea)

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    Here, we report the draft genome sequence of a metagenome-assembled genome (MAG) of a new Alkaliphilus bacterium, NP8, of the Clostridiaceae family. This bacterium was isolated from polluted sediment collected from an abandoned industrial site located in the Gulf of Naples (Mediterranean Sea) as part of a microbial consortium

    Microbiome enrichment from contaminated marine sediments unveils novel bacterial strains for petroleum hydrocarbon and heavy metal bioremediation

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    Petroleum hydrocarbons and heavy metals are some of the most widespread contaminants affecting marine ecosystems, urgently needing effective and sustainable remediation solutions. Microbial-based bioremediation is gaining increasing interest as an effective, economically and environmentally sustainable strategy. Here, we hypothesized that the heavily polluted coastal area facing the Sarno River mouth, which discharges >3 tons of polycyclic aromatic hydrocarbons (PAHs) and ~15 tons of heavy metals (HMs) into the sea annually, hosts unique microbiomes including marine bacteria useful for PAHs and HMs bioremediation. We thus enriched the microbiome of marine sediments, contextually selecting for HM-resistant bacteria. The enriched mixed bacterial culture was subjected to whole-DNA sequencing, metagenome-assembled-genomes (MAGs) annotation, and further sub-culturing to obtain the major bacterial species as pure strains

    Tissue expression of lactate transporters (MCT1 and MCT4) and prognosis of malignant pleural mesothelioma (brief report)

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    Background: Malignant pleural mesothelioma (MPM) is an aggressive neoplasm of the pleura, mainly related to asbestos exposure. As in other solid tumors, malignant cells exhibit high glucose uptake and glycolytic rates with increased lactic acid efflux into the interstitial space. Lactate transport into and out of cells, crucial to maintaining intracellular pH homeostasis and glycolysis, is carried out by monocarboxylate transporters (MCTs) and the chaperone basigin (CD147). We set out to examine the clinical significance of basigin, MCT1 and MCT4 in the context of MPM and to evaluate their expression in relation to the evolution of the disease. Methods: We used immunohistochemistry to measure the expression of basigin, MCT1 and MCT4 in a cohort of 135 individuals with MPM compared to a series of 15 non-MPM pleura specimens. Moreover, by Kaplan-Meier and Cox analyses we evaluated whether an expression over the average of these markers could be associated with the patients' overall survival (OS). Results: We detected positive staining of basigin, MCT1, and MCT4 in most MPM specimens. In particular, MCT4 was always positive in malignant tissues but undetectable in the 4 normal pleural specimens incorporated within the tissue microarray. This was confirmed in the additional series of 15 normal pleural samples. Moreover, MCT4 expression was significantly associated with reduced OS. Conclusion: In this study, the tissue expression of basigin did not prove to be exploitable as a diagnostic or prognostic marker for MPM patients. The expression of MCT1 was not informative either, being tightly correlated with that of basigin. However, the expression of MCT4 showed promise as a diagnostic/therapeutic and prognostic biomarker
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