1,139 research outputs found

    All-optical switching of photonic entanglement

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    Future quantum optical networks will require the ability to route entangled photons at high speeds, with minimal loss and added in-band noise, and---most importantly---without disturbing the photons' quantum state. Here we present an all-optical switch which fulfills these requirements and characterize its performance at the single photon level. It exhibits a 200-ps switching window, 120:1 contrast, 1.5-dB loss, and induces no measurable degradation in the switched photons' entangled-state fidelity (< 0.002). As a proof-of-principle demonstration of its capability, we use the switch to demultiplex a single quantum channel from a dual-channel, time-division-multiplexed entangled photon stream. Furthermore, because this type of switch couples the temporal and spatial degrees of freedom, it provides an important new tool with which to encode multiple-qubit quantum states on a single photon

    Who holds the purse strings within the household? The determinants of intra-family decision making

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    We study the determinants of intra-household decision-making responsibility over economic and financial choices using a direct measure provided in the 1989–2010 Bank of Italy Survey of Household Income and Wealth. We find that the probability that the wife is responsible for decisions increases as the wife’s characteristics in terms of age, education and income become closer or even higher than those of her husband’s. Thus, consistently with a bargaining approach, decision-making responsibility is associated with marriage heterogamy, and not only along strictly economic dimensions. However, in support of an alternative household production approach, we also find that the probability that the wife is responsible is lower when she is employed, which suggests the presence of a specialization pattern assigning responsibility to the spouse with more available time. Our results are robust to additional controls and alternative samples

    Coherent Vector Meson Photo-Production from Deuterium at Intermediate Energies

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    We analyze the cross section for vector meson photo-production off a deuteron for the intermediate range of photon energies starting at a few GeVs above the threshold and higher. We reproduce the steps in the derivation of the conventional non-relativistic Glauber expression based on an effective diagrammatic method while making corrections for Fermi motion and intermediate energy kinematic effects. We show that, for intermediate energy vector meson production, the usual Glauber factorization breaks down and we derive corrections to the usual Glauber method to linear order in longitudinal nucleon momentum. The purpose of our analysis is to establish methods for probing interesting physics in the production mechanism for phi-mesons and heavier vector mesons. We demonstrate how neglecting the breakdown of Glauber factorization can lead to errors in measurements of basic cross sections extracted from nuclear data.Comment: 41 pages, 13 figures, figure 9 is compressed from previous version, typos fixe

    Diffractive Phenomena and Shadowing in Deep-Inelastic Scattering

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    Shadowing effects in deep-inelastic lepton-nucleus scattering probe the mass spectrum of diffractive leptoproduction from individual nucleons. We explore this relationship using current experimental information on both processes. In recent data from the NMC and E665 collaboration, taken at small x << 0.1 and Q^2 < 1 GeV^2, shadowing is dominated by the diffractive excitation and coherent interaction of low mass vector mesons. If shadowing is explored at small x > 1 GeV^2 as discussed at HERA, the situation is different. Here dominant contributions come from the coherent interaction of diffractively produced heavy mass states. Furthermore we observe that the energy dependence of shadowing is directly related to the mass dependence of the diffractive production cross section for free nucleon targets.Comment: 12 pages Latex, 8 figure

    Scattering from Singular Potentials in Quantum Mechanics

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    In non-relativistic quantum mechanics, singular potentials in problems with spherical symmetry lead to a Schrodinger equation for stationary states with non-Fuchsian singularities both as r tends to zero and as r tends to infinity. In the sixties, an analytic approach was developed for the investigation of scattering from such potentials, with emphasis on the polydromy of the wave function in the r variable. The present paper extends those early results to an arbitrary number of spatial dimensions. The Hill-type equation which leads, in principle, to the evaluation of the polydromy parameter, is obtained from the Hill equation for a two-dimensional problem by means of a simple change of variables. The asymptotic forms of the wave function as r tends to zero and as r tends to infinity are also derived. The Darboux technique of intertwining operators is then applied to obtain an algorithm that makes it possible to solve the Schrodinger equation with a singular potential containing many negative powers of r, if the exact solution with even just one term is already known.Comment: 19 pages, plain Tex. In this revised version, the analysis of Eq. (5.29) has been amended, and an appendix has been added for completenes

    Glutamine deprivation enhances antitumor activity of 3-bromopyruvate through the stabilization of monocarboxylate transporter-1

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    Anticancer drug efficacy might be leveraged by strategies to target certain biochemical adaptations of tumors. Here we show how depriving cancer cells of glutamine can enhance the anticancer properties of 3-bromopyruvate, a halogenated analog of pyruvic acid. Glutamine deprival potentiated 3-bromopyruvate chemotherapy by increasing the stability of the monocarboxylate transporter-1, an effect that sensitized cells to metabolic oxidative stress and autophagic cell death. We further elucidated mechanisms through which resistance to chemopotentiation by glutamine deprival could be circumvented. Overall, our findings offer a preclinical proof-of-concept for how to employ 3-bromopyruvate or other monocarboxylic-based drugs to sensitize tumors to chemotherap

    Color Transparency Effects in Electron Deuteron Interactions at Intermediate Q^2

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    High momentum transfer electrodisintegration of polarized and unpolarized deuterium targets, d(e,ep)nd(e,e'p)n is studied. We show that the importance of final state interactions-FSI, occuring when a knocked out nucleon interacts with the other nucleon, depends strongly on the momentum of the spectator nucleon. In particular, these FSI occur when the essential contributions to the scattering amplitude arise from internucleon distances 1.5 fm\sim 1.5~fm. But the absorption of the high momentum γ\gamma^* may produce a point like configuration, which evolves with time. In this case, the final state interactions probe the point like configuration at the early stage of its evolution. The result is that significant color transparency effects, which can either enhance or suppress computed cross sections, are predicted to occur for 4GeV2Q2 10 (GeV/c)2\sim 4 GeV^2 \ge Q^2\leq~10~(GeV/c)^2.Comment: 37 pages LaTex, 12 uuencoded PostScript Figures as separate file, to be published in Z.Phys.

    Solitary intrathyroidal metastasis of renal clear cell carcinoma in a toxic substernal multinodular goiter.

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    INTRODUCTION: Thyroid gland is a rare site of clinically detectable tumor metastasis. CASE REPORT: A 71-year-old woman was referred to our department for an evaluation of toxic multinodular substernal goiter. She had a history of renal clear cell carcinoma of the left kidney, which had been resected 2 years previously. US confirmed the multinodular goiter. Total thyroidectomy with neuromonitoring was performed on March 2008. A histological examination revealed a solitary metastasis of a clear cell renal cancer in a diffuse multinodular goiter. No distant metastases are detected. CONCLUSION: Although uncommon, it is important for the endocrine surgeon and endocrine oncologist to be able to recognize and differentiate intrathyroid metastases from more primary common thyroid neoplasms. The diagnosis can be suspected if the patient has a thyroid tumor and a past history of extrathyroid cancer. These tumors, on the whole, tend to behave more aggressively and, in most cases, the use of multimodality therapy is recommende

    Calculations of the Exclusive Processes 2H(e,e'p)n, 3He(e,e'p)2H and 3He(e,e'p)(pn) within a Generalized Glauber Approach

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    The exclusive processes 2H(e,e'p)n, 3He(e,e'p)2H and 3He(e,e'p)(pn), have been analyzed using realistic few-body wave functions and treating the final state interaction (FSI) within a Generalized Eikonal Approximation (GEA), based upon the direct calculation of the Feynman diagrams describing the rescattering of the struck nucleon with the nucleons of the A-1 system. The approach represents an improvement of the conventional Glauber approach (GA), in that it allows one to take into account the effects of the nuclear excitation of the A1A-1 system on the rescattering of the struck nucleon. Using realistic three-body wave functions corresponding to the AV18 interaction, the results of our parameter free calculations are compared with available experimental data. It is found that in some kinematical conditions FSI effects represent small corrections, whereas in other kinematics conditions they are very large and absolutely necessary to provide a satisfactory agreement between theoretical calculations and experimental data. It is shown that in the kinematics of the experimental data which have been considered, covering the region of missing momentum and energy with p_m < 0.6 GeV/c and E_m < 100 MeV in the perpendicular kinematics, the GA and GEA predictions differ only by less than 3-4 %.Comment: Typos detected and removed while Proof reading. Physical Review C. in Pres
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