1,032 research outputs found
Parallel Quantum Computing Emulation
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
Objetivo:
Comprobar la especificidad de la tomografĂa abdominal sin
contraste en el diagnĂłstico de apendicitis aguda perforada
Material y métodos:
Se llevĂł 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 lĂquido libre apendicular en el diagnĂłstico de apendicitis aguda perforada fue de 93%; 77%; 88% y 83% respectivamente, del apendicolito en el diagnĂłstico de apendicitis aguda perforada fue de 83%; 87%; 92% y 74% respectivamente, de la razĂłn longitud diámetro apendicular en el diagnĂłstico de apendicitis aguda perforada fue de 80%; 97%; 98% y 73% respectivamente.
ConclusiĂłn:
La tomografĂa abdominal sin contraste tiene especificidad en el
diagnĂłstico 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
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
<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
Optical Ranging Overview and Analysis of Calibration Data
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 AFLOW Fleet for Materials Discovery
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
The Cosmic Microwave Background and Particle Physics
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
© 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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