2,203 research outputs found
Dissipation-driven generation of two-qubit entanglement mediated by plasmonic waveguides
We study the generation of entanglement between two distant qubits mediated
by the surface plasmons of a metallic waveguide. We show that a V-shaped
channel milled in a flat metallic surface is much more efficient for this
purpose than a metallic cylinder. The role of the misalignments of the dipole
moments of the qubits, an aspect of great importance for experimental
implementations, is also studied. A careful analysis of the quantum-dynamics of
the system by means of a master equation shows that two-qubit entanglement
generation is essentially due to the dissipative part of the effective
qubit-qubit coupling provided by the surface plasmons. The influence of a
coherent external pumping, needed to achieve a steady state entanglement, is
discussed. Finally, we pay attention to the question of how to get information
experimentally on the degree of entanglement achieved in the system.Comment: 13 pages, 12 figure
A ferric guest inside a spin crossover ferrous helicate
A designed dimetallic Fe(II) helicate made with biphenylenebridged bispyrazolylpyridine ligands and exhibiting a process of spin crossover at temperatures above ambient is shown to encapsulate an S = 5/2 tris-oxalato Fe(III) ion. The spin relaxation dynamics of this guest are strongly reduced upon encapsulatio
FPGA acceleration using high-level languages of a Monte-Carlo method for pricing complex options
This is the author’s version of a work that was accepted for publication in Journal of Systems Architecture. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Systems Architecture, 59, 3 (2013) DOI: 10.1016/j.sysarc.2013.01.004In this paper we present an FPGA implementation of a Monte-Carlo method for pricing Asian options using Impulse C and floating-point arithmetic. In an Altera Stratix-V FPGA, a 149x speedup factor was obtained against an OpenMP-based solution in a 4-core Intel Core i7 processor. This speedup is comparable to that reported in the literature using a classic HDL-based methodology, but the development time is significantly reduced. Additionally, the use of a HLL-based methodology allowed us to implement a high-quality Gaussian random number generator, which produces more precise results than those obtained with the simple generators usually present in HDL-based designs
Anomalies in Noncommutative Dipole Field Theories
We study chiral symmetries of fermionic non commutative dipole theories. By
using Fujikawa's approach we obtain explicit expressions of the anomalies for
Dirac and chiral fermions in 2 and 4 dimensions.Comment: 11pages, latex file. Comments adde
PvGAMA reticulocyte binding activity: predicting conserved functional regions by natural selection analysis
Background: Adhesin proteins are used by Plasmodium parasites to bind and invade target cells. Hence, characterising molecules that participate in reticulocyte interaction is key to understanding the molecular basis of Plasmodium vivax invasion. This study focused on predicting functionally restricted regions of the P. vivax GPI-anchored micronemal antigen (PvGAMA) and characterising their reticulocyte binding activity. Results: The pvgama gene was initially found in P. vivax VCG-I strain schizonts. According to the genetic diversity analysis, PvGAMA displayed a size polymorphism very common for antigenic P. vivax proteins. Two regions along the antigen sequence were highly conserved among species, having a negative natural selection signal. Interestingly, these regions revealed a functional role regarding preferential target cell adhesion. Conclusions: To our knowledge, this study describes PvGAMA reticulocyte binding properties for the first time. Conserved functional regions were predicted according to natural selection analysis and their binding ability was confirmed. These findings support the notion that PvGAMA may have an important role in P. vivax merozoite adhesion to its target cells. © 2017 The Author(s)
A low-power RF front-end for 2.5 GHz receivers
© 2008 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper presents a low power and low cost front end for a direct conversion 2.5 GHz ISM band receiver composed of a 16 kV HBM ESD protected LNA, differential Gilbert-cell mixers, and high-pass filters for DC offset cancellation. The whole front-end is implemented in a 2P6M 0.18 µm RFCMOS process. It exhibits a voltage gain of 24dB and a SSB noise figure of 8.4dB which make it suitable for most of the 2.5 GHz wireless short-range communication transceivers. The achieved power consumption is only 1.06mW from a 1.2V power supply.Peer ReviewedPostprint (published version
The contribution of histone crotonylation to tissue health and disease: focus on kidney health
Acute kidney injury (AKI) and chronic kidney disease (CKD) are the most severe
consequences of kidney injury. They are interconnected syndromes as CKD
predisposes to AKI and AKI may accelerate CKD progression. Despite their growing
impact on the global burden of disease, there is no satisfactory treatment for AKI and
current therapeutic approaches to CKD remain suboptimal. Recent research has focused
on the therapeutic target potential of epigenetic regulation of gene expression, including
non-coding RNAs and the covalent modifications of histones and DNA. Indeed, several
drugs targeting histone modifications are in clinical use or undergoing clinical trials. Acyllysine
histone modifications (e.g. methylation, acetylation, and crotonylation) have
modulated experimental kidney injury. Most recently, increased histone lysine
crotonylation (Kcr) was observed during experimental AKI and could be reproduced in
cultured tubular cells exposed to inflammatory stress triggered by the cytokine TWEAK.
The degree of kidney histone crotonylation was modulated by crotonate availability and
crotonate supplementation protected from nephrotoxic AKI. We now review the functional
relevance of histone crotonylation in kidney disease and other pathophysiological
contexts, as well as the implications for the development of novel therapeutic
approaches. These studies provide insights into the overall role of histone crotonylation in health and diseaseSources of support: FIS/FEDER funds (PI15/00298, CP14/00133,
PI16/02057, PI16/01900, PI18/01386, PI19/00588, PI19/00815,
DTS18/00032, ERA-PerMed-JTC2018 (KIDNEY ATTACK
AC18/00064 and PERSTIGAN AC18/00071), ISCIII-RETIC
REDinREN RD016/0009), Sociedad Española de Nefrología,
FRIAT, Comunidad de Madrid en Biomedicina B2017/BMD-
3686 CIFRA2-CM. Salary support: ISCIII Miguel Servet and to
AS and MS-N, ISCIII Sara Borrell to JM-M and Comunidad de
Madrid (B2017/BMD-3686 CIFRA2-CM) to MF-B and DM-S
A new vertebrate assemblage from the matute formation of the Cameros Basin (Ágreda, Spain): implications for the diversity during the jurassic/cretaceous boundary
Altres ajuts: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.The Ribota site (Ágreda, Soria, Spain) is a new locality in the Matute Formation (Tithonian-Berriasian) composed of several carbonate layers, outstandingly rich in macrovertebrate remains. Fossils show an unusual replacement of the original bioapatite by quartz, and are found as positive reliefs protruding from lacustrine limestone beds. This type of conservation has allowed the identification of around one hundred vertebrate bone accumulations in an outcrop of more than 10 hectares. Osteichthyans (articulated partial skeletons, cranial material, and isolated postcranial bones and scales), crocodylomorphs (disarticulated cranial material, isolated teeth, vertebrae and osteoderms), turtles (partial carapaces and plastra, but also isolated plates) and pterosaurs (cranial and appendicular elements) have been identified. Around 80 specimens have been collected and a preliminary study of part of the collection (35 specimens) has allowed the identification of at least 5 different taxa: Halecomorphi indet., Neoginglymodi indet., Goniopholididae indet., Testudinata indet., and Pterodactyloidea indet. This new site represents one of the few sites from this time interval preserved in a fully lacustrine environment, so these vertebrate assemblages are unique and composed of different animals that presumably lived around and within the lake. They are dominated by aquatic and amphibian vertebrates and was formed by attrition in this lacustrine environment, possibly far from the lake shoreline. These macrovertebrate assemblages provide new data about the diversity in the faunal ecosystems from the Jurassic/Cretaceous transition of the Iberian Basin Rift System
Self-organized network evolution coupled to extremal dynamics
The interplay between topology and dynamics in complex networks is a
fundamental but widely unexplored problem. Here, we study this phenomenon on a
prototype model in which the network is shaped by a dynamical variable. We
couple the dynamics of the Bak-Sneppen evolution model with the rules of the
so-called fitness network model for establishing the topology of a network;
each vertex is assigned a fitness, and the vertex with minimum fitness and its
neighbours are updated in each iteration. At the same time, the links between
the updated vertices and all other vertices are drawn anew with a
fitness-dependent connection probability. We show analytically and numerically
that the system self-organizes to a non-trivial state that differs from what is
obtained when the two processes are decoupled. A power-law decay of dynamical
and topological quantities above a threshold emerges spontaneously, as well as
a feedback between different dynamical regimes and the underlying correlation
and percolation properties of the network.Comment: Accepted version. Supplementary information at
http://www.nature.com/nphys/journal/v3/n11/suppinfo/nphys729_S1.htm
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