3,395 research outputs found
Hybrid quantum repeater using bright coherent light
We describe a quantum repeater protocol for long-distance quantum
communication. In this scheme, entanglement is created between qubits at
intermediate stations of the channel by using a weak dispersive light-matter
interaction and distributing the outgoing bright coherent light pulses among
the stations. Noisy entangled pairs of electronic spin are then prepared with
high success probability via homodyne detection and postselection. The local
gates for entanglement purification and swapping are deterministic and
measurement-free, based upon the same coherent-light resources and weak
interactions as for the initial entanglement distribution. Finally, the
entanglement is stored in a nuclear-spin-based quantum memory. With our system,
qubit-communication rates approaching 100 Hz over 1280 km with fidelities near
99% are possible for reasonable local gate errors.Comment: title changed, final published versio
DIOS: the dark baryon exploring mission
DIOS (Diffuse Intergalactic Oxygen Surveyor) is a small satellite aiming for
a launch around 2020 with JAXA's Epsilon rocket. Its main aim is a search for
warm-hot intergalactic medium with high-resolution X-ray spectroscopy of
redshifted emission lines from OVII and OVIII ions. The superior energy
resolution of TES microcalorimeters combined with a very wide field of view
(30--50 arcmin diameter) will enable us to look into gas dynamics of cosmic
plasmas in a wide range of spatial scales from Earth's magnetosphere to
unvirialized regions of clusters of galaxies. Mechanical and thermal design of
the spacecraft and development of the TES calorimeter system are described. We
also consider revising the payload design to optimize the scientific capability
allowed by the boundary conditions of the small mission.Comment: 10 pages, 11 figures, Proceedings of the SPIE Astronomical
Instrumentation : Space Telescopes and Instrumentation 2014: Ultraviolet to
Gamma Ra
Correlated oscillations in Kerr parametric oscillators with tunable effective coupling
We study simultaneous parametric oscillations in a system composed of two
distributed-element-circuit Josephson parametric oscillators in the
single-photon Kerr regime coupled via a static capacitance. The energy of the
system is described by a two-bit Ising Hamiltonian with an effective coupling
whose amplitude and sign depend on the relative phase between parametric pumps.
We demonstrate that the binary phases of the parametric oscillations are
correlated with each other, and that the parity and strength of the correlation
can be controlled by adjusting the pump phase. The observed correlation is
reproduced in our simulation taking pure dephasing into account. The present
result demonstrates the tunability of the Hamiltonian parameters by the phase
of external microwave, which can be used in the the Ising machine hardware
composed of the KPO network.Comment: 9 pages, 8 figure
Prediction of transcriptional regulatory elements for plant hormone responses based on microarray data
<p>Abstract</p> <p>Background</p> <p>Phytohormones organize plant development and environmental adaptation through cell-to-cell signal transduction, and their action involves transcriptional activation. Recent international efforts to establish and maintain public databases of <it>Arabidopsis </it>microarray data have enabled the utilization of this data in the analysis of various phytohormone responses, providing genome-wide identification of promoters targeted by phytohormones.</p> <p>Results</p> <p>We utilized such microarray data for prediction of <it>cis</it>-regulatory elements with an octamer-based approach. Our test prediction of a drought-responsive RD29A promoter with the aid of microarray data for response to drought, ABA and overexpression of DREB1A, a key regulator of cold and drought response, provided reasonable results that fit with the experimentally identified regulatory elements. With this succession, we expanded the prediction to various phytohormone responses, including those for abscisic acid, auxin, cytokinin, ethylene, brassinosteroid, jasmonic acid, and salicylic acid, as well as for hydrogen peroxide, drought and DREB1A overexpression. Totally 622 promoters that are activated by phytohormones were subjected to the prediction. In addition, we have assigned putative functions to 53 octamers of the Regulatory Element Group (REG) that have been extracted as position-dependent <it>cis</it>-regulatory elements with the aid of their feature of preferential appearance in the promoter region.</p> <p>Conclusions</p> <p>Our prediction of <it>Arabidopsis cis</it>-regulatory elements for phytohormone responses provides guidance for experimental analysis of promoters to reveal the basis of the transcriptional network of phytohormone responses.</p
Allie: a database and a search service of abbreviations and long forms
Many abbreviations are used in the literature especially in the life sciences, and polysemous abbreviations appear frequently, making it difficult to read and understand scientific papers that are outside of a reader’s expertise. Thus, we have developed Allie, a database and a search service of abbreviations and their long forms (a.k.a. full forms or definitions). Allie searches for abbreviations and their corresponding long forms in a database that we have generated based on all titles and abstracts in MEDLINE. When a user query matches an abbreviation, Allie returns all potential long forms of the query along with their bibliographic data (i.e. title and publication year). In addition, for each candidate, co-occurring abbreviations and a research field in which it frequently appears in the MEDLINE data are displayed. This function helps users learn about the context in which an abbreviation appears. To deal with synonymous long forms, we use a dictionary called GENA that contains domain-specific terms such as gene, protein or disease names along with their synonymic information. Conceptually identical domain-specific terms are regarded as one term, and then conceptually identical abbreviation-long form pairs are grouped taking into account their appearance in MEDLINE. To keep up with new abbreviations that are continuously introduced, Allie has an automatic update system. In addition, the database of abbreviations and their long forms with their corresponding PubMed IDs is constructed and updated weekly
Ferromagnetism and large negative magnetoresistance in Pb doped Bi-Sr-Co-O misfit-layer compound
Ferromagnetism and accompanying large negative magnetoresistance in
Pb-substituted Bi-Sr-Co-O misfit-layer compound are investigated in detail.
Recent structural analysis of (Bi,Pb)SrCoO, which has
been believed to be a Co analogue of
BiSrCaCuO, revealed that it has a more complex
structure including a CoO hexagonal layer [T. Yamamoto {\it et al.}, Jpn.
J. Appl. Phys. {\bf 39} (2000) L747]. Pb substitution for Bi not only
introduces holes into the conducting CoO layers but also creates a
certain amount of localized spins. Ferromagnetic transition appears at =
3.2 K with small spontaneous magnetization along the axis, and around the
transition temperature large and anisotropic negative magnetoresistance was
observed. This compound is the first example which shows ferromagnetic
long-range order in a two-dimensional metallic hexagnonal CoO layer.Comment: 8 pages including eps figures. To be published in J. Phys. Soc. Jp
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