303 research outputs found

    Generation of two-photon EPR and Wstates

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    In this paper we present a scheme for generation of two-photon EPR and W states in the cavity QED context. The scheme requires only one three-level Rydberg atom and two or three cavities. The atom is sent to interact with cavities previously prepared in vacuum states, via two-photon process. An appropriate choice of the interaction times one obtains the mentioned state with maximized fidelities. These specific times and the values of success probability and fidelity are discussed.Comment: 4 pages, 5 figure

    A Voting-Based System for Ethical Decision Making

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    We present a general approach to automating ethical decisions, drawing on machine learning and computational social choice. In a nutshell, we propose to learn a model of societal preferences, and, when faced with a specific ethical dilemma at runtime, efficiently aggregate those preferences to identify a desirable choice. We provide a concrete algorithm that instantiates our approach; some of its crucial steps are informed by a new theory of swap-dominance efficient voting rules. Finally, we implement and evaluate a system for ethical decision making in the autonomous vehicle domain, using preference data collected from 1.3 million people through the Moral Machine website.Comment: 25 pages; paper has been reorganized, related work and discussion sections have been expande

    A rare pediatric renal tumor: classic congenital mesoblastic nephroma: two cases and review of literature

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    Background Mesoblastic nephroma (Boland’s tumor) is the most common benign renal tumor occurring in infants and neonates. The most common presentation is abdominal mass, but it can have varied presentations because of associated paraneoplastic syndromes. Majority of these tumors can be cured with surgical excision alone; however, long-term follow-up is required for recurrence or metastasis. Histopathologically, it is divided into two subtypes: classic and cellular. The less common cellular congenital mesoblastic nephromas have cellular elements in them and tend to have a more malignant potential.Patients and methods Two patients were studied over a period of 2 years from June 2010 to June 2012.Results By reporting two patients presenting in the infantile period with classic congenital mesoblastic nephromas, an attempt is made in this paper to characterize the clinical behavior of this variety of renal tumors. Hypertension and paraneoplastic syndromes can be associated with this tumor. Herein we compare our experience with other similar cases reported in the literature.Conclusion When renal tumors occur in infancy or at neonatal age, mesoblastic nephroma should be kept in mind. Association of hypertension and paraneoplastic syndromes should be looked for. Surgery is usually curative and postoperative follow-up for recurrence is required, more so in cellular variety

    ACL reconstruction with Lateral Extra-articular Tenodesis

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    There is a renewed interest in the Anterolateral complex (ALC) in the past decade owing to the anatomical study by Claes et al. Increased graft ruptures seen in patients exhibiting high-grade pivot-shift led to a necessity to combine an extra-articular procedure along with arthroscopic ACL reconstruction (ACLR). In this article, we describe a case involving a young patient with hyperlaxity who underwent a primary arthroscopic ACLR with Lateral extra-articular tenodesis (LET) along with review of literature

    Optical Tracer Size Differences Allow Quantitation of Active Pumping Rate Versus Stokes–Einstein Diffusion in Lymphatic Transport

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    Lymphatic uptake of interstitially administered agents occurs by passive convective–diffusive inflow driven by interstitial concentration and pressure, while the downstream lymphatic transport is facilitated by active propulsive contractions of lymphatic vessel walls. Near-infrared fluorescence imaging in mice was used to measure these central components of lymphatic transport for the first time, using two different-sized molecules––methylene blue (MB) and fluorescence-labeled antibody immunoglobulin G (IgG)-IRDye 680RD. This work confirms the hypothesis that lymphatic passive inflow and active propulsion rates can be separated based upon the relative differences in Stokes–Einstein diffusion coefficient. This coefficient specifically affects the passive-diffusive uptake when the interstitial volume and pressure are constant. Parameters such as mean time-to-peak signal, overall fluorescence signal intensities, and number of active peristaltic pulses, were estimated from temporal imaging data. While the mean time to attain peak signal representative of diffusion-dominated flow in the lymph vessels was 0.6±0.2  min for MB and 8±6  min for IgG, showing a size dependence, the active propulsion rates were 3.4±0.8  pulses/min and 3.3±0.5  pulses/min, respectively, appearing size independent. The propulsion rates for both dyes decreased with clearance from the interstitial injection-site, indicating intrinsic control of the smooth muscles in response to interstitial pressure. This approach to size-comparative agent flow imaging of lymphatic function can enable noninvasive characterization of diseases related to uptake and flow in lymph networks

    Review of Fluorescence Guided Surgery Systems: Identification of Key Performance Capabilities Beyond Indocyanine Green Imaging

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    There is growing interest in using fluorescence imaging instruments to guide surgery, and the leading options for open-field imaging are reviewed here. While the clinical fluorescence-guided surgery (FGS) field has been focused predominantly on indocyanine green (ICG) imaging, there is accelerated development of more specific molecular tracers. These agents should help advance new indications for which FGS presents a paradigm shift in how molecular information is provided for resection decisions. There has been a steady growth in commercially marketed FGS systems, each with their own differentiated performance characteristics and specifications. A set of desirable criteria is presented to guide the evaluation of instruments, including: (i) real-time overlay of white-light and fluorescence images, (ii) operation within ambient room lighting, (iii) nanomolar-level sensitivity, (iv) quantitative capabilities, (v) simultaneous multiple fluorophore imaging, and (vi) ergonomic utility for open surgery. In this review, United States Food and Drug Administration 510(k) cleared commercial systems and some leading premarket FGS research systems were evaluated to illustrate the continual increase in this performance feature base. Generally, the systems designed for ICG-only imaging have sufficient sensitivity to ICG, but a fraction of the other desired features listed above, with both lower sensitivity and dynamic range. In comparison, the emerging research systems targeted for use with molecular agents have unique capabilities that will be essential for successful clinical imaging studies with low-concentration agents or where superior rejection of ambient light is needed. There is no perfect imaging system, but the feature differences among them are important differentiators in their utility, as outlined in the data and tables here
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