1,032 research outputs found

    Parallel Quantum Computing Emulation

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    Quantum computers provide a fundamentally new computing paradigm that promises to revolutionize our ability to solve broad classes of problems. Surprisingly, the basic mathematical structures of gate-based quantum computing, such as unitary operations on a finite-dimensional Hilbert space, are not unique to quantum systems but may be found in certain classical systems as well. Previously, it has been shown that one can represent an arbitrary multi-qubit quantum state in terms of classical analog signals using nested quadrature amplitude modulated signals. Furthermore, using digitally controlled analog electronics one may manipulate these signals to perform quantum gate operations and thereby execute quantum algorithms. The computational capacity of a single signal is, however, limited by the required bandwidth, which scales exponentially with the number of qubits when represented using frequency-based encoding. To overcome this limitation, we introduce a method to extend this approach to multiple parallel signals. Doing so allows a larger quantum state to be emulated with the same gate time required for processing frequency-encoded signals. In the proposed representation, each doubling of the number of signals corresponds to an additional qubit in the spatial domain. Single quit gate operations are similarly extended so as to operate on qubits represented using either frequency-based or spatial encoding schemes. Furthermore, we describe a method to perform gate operations between pairs of qubits represented using frequency or spatial encoding or between frequency-based and spatially encoded qubits. Finally, we describe how this approach may be extended to represent qubits in the time domain as well.Comment: 9 pages, 4 figures, 2018 IEEE International Conference on Rebooting Computing (ICRC

    Eficacia De La TomografĂ­a Abdominal Sin Contraste En El DiagnĂłstico De Apendicitis Aguda Perforada En El Hospital Alta Complejidad Virgen De La Puerta

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    Objetivo: Comprobar la especificidad de la tomografía abdominal sin contraste en el diagnóstico de apendicitis aguda perforada Material y métodos: Se llevó a cabo un estudio en el que se incluyeron a 173 pacientes adultos con apendicitis aguda, los cuales se dividieron en 2 grupos: perforada o no perforada ; calculándose la sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo. Resultados: No se apreciaron diferencias significativas respecto a las variables edad, gene ro, leucocitosis, hiponatremia, plaquetopenia, anisocitosis entre los pacientes con apendicitis perforada o n o per forada (p>0.05), la s sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo del líquido libre apendicular en el diagnóstico de apendicitis aguda perforada fue de 93%; 77%; 88% y 83% respectivamente, del apendicolito en el diagnóstico de apendicitis aguda perforada fue de 83%; 87%; 92% y 74% respectivamente, de la razón longitud diámetro apendicular en el diagnóstico de apendicitis aguda perforada fue de 80%; 97%; 98% y 73% respectivamente. Conclusión: La tomografía abdominal sin contraste tiene especificidad en el diagnóstico de apendicitis aguda perforadaObjecti ve: T o veri fy the specificity of abdominal tomography without contrast in the diagno sis of acute perforated appendicitis in patients Material and m ethods: A retrospective sectional study in 173 adult patients with acute appendicitis were included, which w ere d i vided into 2 groups: pe rforated or non perforated; calculating sensitivity, sp ecificity, positive predictive value and negative predictive val ue. Results: No significant differences were observed regarding the variables age, gender, leukocytosis, hyp onatr e mia, plateletopenia, an isocytosis between patients with perforated or non perf orated appendicitis (p>0.05), the sensitivity, specificity, posi tive predictive value and negative predictive value of the Appendiceal free fluid in the diagnosis of acute perfo r ated appendicitis was 9 3%; 77%; 88% and 83% respectively, of the appendicolith in the diagnosis of acute perforated appendicitis was 83%; 87%; 92% and 74% respectively, of the appendiceal diameter length ratio in the diagnosis of acute perforated app endic i tis was 80%; 97%; 98% a nd 73% respectively. Conclusion: Abdominal to mography w ithout contrast had specificity in the diagnosis of acute perfor ated appendicitis in patientsTesi

    A Noncoherent Space-Time Code from Quantum Error Correction

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    In this work, we develop a space-time block code for noncoherent communication using techniques from the field of quantum error correction. We decompose the multiple-input multiple-output (MIMO) channel into operators from quantum mechanics, and design a non-coherent space time code using the quantum stabilizer formalism. We derive an optimal decoder, and analyze the former through a quantum mechanical lens. We compare our approach to a comparable coherent approach and a noncoherent differential approach, achieving comparable or better performance.Comment: 6 pages, one figure, accepted at the 53rd annual Conference on Information Sciences and System

    Plant neighbor identity influences plant biochemistry and physiology related to defense

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    <p>Abstract</p> <p>Background</p> <p>Chemical and biological processes dictate an individual organism's ability to recognize and respond to other organisms. A small but growing body of evidence suggests that plants may be capable of recognizing and responding to neighboring plants in a species specific fashion. Here we tested whether or not individuals of the invasive exotic weed, <it>Centaurea maculosa</it>, would modulate their defensive strategy in response to different plant neighbors.</p> <p>Results</p> <p>In the greenhouse, <it>C. maculosa </it>individuals were paired with either conspecific (<it>C. maculosa</it>) or heterospecific (<it>Festuca idahoensis</it>) plant neighbors and elicited with the plant defense signaling molecule methyl jasmonate to mimic insect herbivory. We found that elicited <it>C. maculosa </it>plants grown with conspecific neighbors exhibited increased levels of total phenolics, whereas those grown with heterospecific neighbors allocated more resources towards growth. To further investigate these results in the field, we conducted a metabolomics analysis to explore chemical differences between individuals of <it>C. maculosa </it>growing in naturally occurring conspecific and heterospecific field stands. Similar to the greenhouse results, <it>C. maculosa </it>individuals accumulated higher levels of defense-related secondary metabolites and lower levels of primary metabolites when growing in conspecific versus heterospecific field stands. Leaf herbivory was similar in both stand types; however, a separate field study positively correlated specialist herbivore load with higher densities of <it>C. maculosa </it>conspecifics.</p> <p>Conclusions</p> <p>Our results suggest that an individual <it>C. maculosa </it>plant can change its defensive strategy based on the identity of its plant neighbors. This is likely to have important consequences for individual and community success.</p

    The AFLOW Fleet for Materials Discovery

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    The traditional paradigm for materials discovery has been recently expanded to incorporate substantial data driven research. With the intent to accelerate the development and the deployment of new technologies, the AFLOW Fleet for computational materials design automates high-throughput first principles calculations, and provides tools for data verification and dissemination for a broad community of users. AFLOW incorporates different computational modules to robustly determine thermodynamic stability, electronic band structures, vibrational dispersions, thermo-mechanical properties and more. The AFLOW data repository is publicly accessible online at aflow.org, with more than 1.7 million materials entries and a panoply of queryable computed properties. Tools to programmatically search and process the data, as well as to perform online machine learning predictions, are also available.Comment: 14 pages, 8 figure

    Optical Ranging Overview and Analysis of Calibration Data

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    Author Institution: Lawrence Livermore National Laboratory; National Security Technologies, LLCSlides presented at the 2016 Photonic Doppler Velocimetry (PDV) unclassified program, Bankhead Theater, Livermore, California, June 7 - 9, 2016. Morning program, June 9, 2016

    The Cosmic Microwave Background and Particle Physics

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    In forthcoming years, connections between cosmology and particle physics will be made increasingly important with the advent of a new generation of cosmic microwave background (CMB) experiments. Here, we review a number of these links. Our primary focus is on new CMB tests of inflation. We explain how the inflationary predictions for the geometry of the Universe and primordial density perturbations will be tested by CMB temperature fluctuations, and how the gravitational waves predicted by inflation can be pursued with the CMB polarization. The CMB signatures of topological defects and primordial magnetic fields from cosmological phase transitions are also discussed. Furthermore, we review current and future CMB constraints on various types of dark matter (e.g. massive neutrinos, weakly interacting massive particles, axions, vacuum energy), decaying particles, the baryon asymmetry of the Universe, ultra-high-energy cosmic rays, exotic cosmological topologies, and other new physics.Comment: 43 pages. To appear in Annual Reviews of Nuclear and Particle Scienc

    Reflective imaging improves spatiotemporal resolution and collection efficiency in light sheet microscopy

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    © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nature Communications 8 (2017): 1452, doi:10.1038/s41467-017-01250-8.Light-sheet fluorescence microscopy (LSFM) enables high-speed, high-resolution, and gentle imaging of live specimens over extended periods. Here we describe a technique that improves the spatiotemporal resolution and collection efficiency of LSFM without modifying the underlying microscope. By imaging samples on reflective coverslips, we enable simultaneous collection of four complementary views in 250 ms, doubling speed and improving information content relative to symmetric dual-view LSFM. We also report a modified deconvolution algorithm that removes associated epifluorescence contamination and fuses all views for resolution recovery. Furthermore, we enhance spatial resolution (to <300 nm in all three dimensions) by applying our method to single-view LSFM, permitting simultaneous acquisition of two high-resolution views otherwise difficult to obtain due to steric constraints at high numerical aperture. We demonstrate the broad applicability of our method in a variety of samples, studying mitochondrial, membrane, Golgi, and microtubule dynamics in cells and calcium activity in nematode embryos.This work was supported by the Intramural Research Program of the National Institute of Biomedical Imaging and Bioengineering at the National Institutes of Health. P.L. and H.S. acknowledge summer support from the Marine Biological Laboratory at Woods Hole, through the Whitman- and Fellows- program. P.L. acknowledges support from NIH National Institute of Biomedical Imaging and Bioengineering (NIBIB) of the National Institutes of Health (NIH) under grant number R01EB017293. C.S. acknowledges funding from the National Institute of General Medical Sciences of NIH under Award Number R25GM109439 (Project Title: University of Chicago Initiative for Maximizing Student Development [IMSD]) and NIBIB under grant number T32 EB002103. Partial funding for the computation in this work was provided by NIH grant numbers S10 RRO21039 and P30 CA14599. A.U. and I.R.-S. were supported by the NSF grant number 1607645
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