7,454 research outputs found
Ultrarobust calibration of an optical lattice depth based on a phase shift
We report on a new method to calibrate the depth of an optical lattice. It
consists in triggering the intrasite dipole mode of the cloud by a sudden phase
shift. The corresponding oscillatory motion is directly related to the
intraband frequencies on a large range of lattice depths. Remarkably, for a
moderate displacement, a single frequency dominates this oscillation for the
zeroth and first order interference pattern observed after a sufficiently long
time-of-flight. The method is robust against atom-atom interactions and the
exact value of the extra external confinement of the initial trapping
potential.Comment: 7 pages, 6 figure
The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC
We analyzed the triple Higgs boson self-coupling at future
colliders energies, with the reactions . We evaluate the total cross-sections for both and ,
and calculate the total number of events considering the complete set of
Feynman diagrams at tree-level. We vary the triple coupling
within the range and +2. The numerical
computation is done for the energies expected to be available at a possible
Future Linear Collider with a center-of-mass energy and a luminosity 1000 . Our analysis is also extended to a
center-of-mass energy 3 and luminosities of 1000 and 5000
. We found that for the process , the
complete calculation differs only by 3% from the approximate calculation
, while for the process , the expected number of events, considering the decay products of both
and , is not enough to obtain an accurate determination of the triple Higgs
boson self-coupling.Comment: 19 pages, 12 figure
Silicon slow-light-based photonic mixer for microwave-frequencyconversion applications
This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.37.001721. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] We describe and demonstrate experimentally a method for photonic mixing of microwave signals by using a silicon electro-optical Mach¿Zehnder modulator enhanced via slow-light propagation. Slow light with a group index of ~11, achieved in a one-dimensional periodic structure, is exploited to improve the upconversion performance of an input frequency signal from 1 to 10.25 GHz. A minimum transmission point is used to successfully demonstrate the upconversion with very low conversion losses of ~7¿¿dB and excellent quality of the received I/Q modulated QPSK signal with an optimum EVM of ~8%.Financial support from FP7-224312 HELIOS project and Generalitat Valenciana under PROMETEO-2010-087 R&D Excellency Program (NANOMET) are acknowledged. F. Y.Gardes, D. J. Thomson, and G. T. Reed are supported by funding received from the UK EPSRC funding body under the grant “UK Silicon Photonics.” The author A. M. Gutiérrez thanks D. Marpaung for his useful
help.Gutiérrez Campo, AM.; Brimont, ACJ.; Herrera Llorente, J.; Aamer, M.; Martí Sendra, J.; Thomson, DJ.; Gardes, FY.... (2012). Silicon slow-light-based photonic mixer for microwave-frequencyconversion applications. Optics Letters. 37(10):1721-1723. https://doi.org/10.1364/OL.37.001721S17211723371
Tissue Localization and Extracellular Matrix Degradation by PI, PII and PIII Snake Venom Metalloproteinases: Clues on the Mechanisms of Venom-Induced Hemorrhage
20 páginas, 4 figuras, 3 tablas y 7 tablas en material suplementario.Snake venom hemorrhagic metalloproteinases (SVMPs) of the PI, PII and PIII classes were compared in terms of tissue localization and their ability to hydrolyze basement membrane components in vivo, as well as by a proteomics analysis of exudates collected in tissue injected with these enzymes. Immunohistochemical analyses of co-localization of these SVMPs with type IV collagen revealed that PII and PIII enzymes co-localized with type IV collagen in capillaries, arterioles and post-capillary venules to a higher extent than PI SVMP, which showed a more widespread distribution in the tissue. The patterns of hydrolysis by these three SVMPs of laminin, type VI collagen and nidogen in vivo greatly differ, whereas the three enzymes showed a similar pattern of degradation of type IV collagen, supporting the concept that hydrolysis of this component is critical for the destabilization of microvessel structure leading to hemorrhage. Proteomic analysis of wound exudate revealed similarities and differences between the action of the three SVMPs. Higher extent of proteolysis was observed for the PI enzyme regarding several extracellular matrix components and fibrinogen, whereas exudates from mice injected with PII and PIII SVMPs had higher amounts of some intracellular proteins. Our results provide novel clues for understanding the mechanisms by which SVMPs induce damage to the microvasculature and generate hemorrhage.This work was performed in partial fulfillment of the requirements for the PhD degree for Cristina Herrera at Universidad de Costa Rica.Peer reviewe
The impact of environmental performance on stock prices in the green and innovative context
.This study examines the impact of environmental performance on firms' stock prices, considering the moderating effect of the green and innovative environmental context by country. Renewable energy policies, green technologies, and foreign trade form this environmental context of interest for the reduction of carbon emissions. Using a sample of 2638 firm-year observations for the firms listed in the main stock index of 16 European countries over the period of 2005–2017, we find that environmental performance is value-relevant, except during the worst years of a crisis, when it is not significant. Two elements of the green technological framework, namely, renewable energy policies and the potential transmission effect of technology through foreign trade, are valued by investors as offsetting factors of the positive effect exerted by carbon performance on the firm's value. This is consistent with the slow and costly adoption of greener technologies. However, registered green patents appear to be a turning point, showing a significant positive effect on the relationship between firms' environmental performances and their market values. Again, the crisis period interferes with deepening the negative effect of renewable energy policies and cancelling out the effect of green patents and foreign trade. On one hand, our results highlight the market's role in making inefficiencies visible and showing the potential future losses of green and innovative policies; on the other hand, the hampering interference of crisis periods must be considered by policymakers.S
Diseño de la trama urbana y cobertura de las redes de transporte público
Una de las claves en su uso del transporte público es la accesibilidad de la población a las paradas o estaciones. Los planificadores del transporte han buscado siempre localizaciones de paradas y estaciones en espacios con un volumen importante de población residente y/o empleo en su entorno inmediato. En los últimos años, se conjugan también políticas urbanísticas para generar nuevos desarrollos urbanos orientados al uso del transporte público. Se busca potenciar las llamadas 3D: densidad, diversidad de usos y diseño urbano. En esta comunicación el objetivo es analizar cómo influye el diseño de la trama urbana en la cobertura de las redes de transporte público (cantidad de población y el empleo en el entorno próximo de las estaciones). La metodología se apoya en el uso de Sistemas de Información Geográfica, sobre los que se han diseñado varios tipos de viarios, y para los que miden las superficies cubiertas y las distancias recorridas a estaciones localizadas en el centro de cada uno de ellos. Posteriormente, se hace un ejercicio de simulación donde se ha tomado el Metro de la ciudad de Madrid, y se han superpuesto sobre todas las estaciones de la red cada uno de los viarios tipo. Así, es posible calcular la población y el empleo cubiertos para cada uno de los escenarios tipo y compararla con la cobertura y la calidad de acceso a las estaciones a través del viario real de la ciudad. Al mantenerse fija las distribuciones de población y empleo, las diferencias se explican exclusivamente por el diseño de la trama urbana. Los resultados muestran como viarios orientados las estaciones incrementan notablemente la población y el empleo cubiertos
Real-Time Big Data Analytics in Smart Cities from LoRa-Based IoT Networks
The currently burst of the Internet of Things (IoT) tech-nologies
implies the emergence of new lines of investigation regarding not only to hardware
and protocols but also to new methods of pro-duced data analysis satisfying the
IoT environment constraints: a real-time and a big data approach. The Real-time
restriction is about the continuous generation of data provided by the endpoints
connected to an IoT network; due to the connection and scaling capabilities of an IoT
network, the amount of data to process is so high that Big data tech-niques
become essential. In this article, we present a system consisting of two main
modules. In one hand, the infrastructure, a complete LoRa based network designed,
tested and deployment in the Pablo de Olavide University and, on the other side, the
analytics, a big data streaming sys-tem that processes the inputs produced by the
network to obtain useful, valid and hidden information.Ministerio de Economía y Competitividad TIN2017-88209-C2-1-
Strictly Toral Dynamics
This article deals with nonwandering (e.g. area-preserving) homeomorphisms of
the torus which are homotopic to the identity and strictly
toral, in the sense that they exhibit dynamical properties that are not present
in homeomorphisms of the annulus or the plane. This includes all homeomorphisms
which have a rotation set with nonempty interior. We define two types of
points: inessential and essential. The set of inessential points is
shown to be a disjoint union of periodic topological disks ("elliptic
islands"), while the set of essential points is an essential
continuum, with typically rich dynamics (the "chaotic region"). This
generalizes and improves a similar description by J\"ager. The key result is
boundedness of these "elliptic islands", which allows, among other things, to
obtain sharp (uniform) bounds of the diffusion rates. We also show that the
dynamics in is as rich as in from the rotational
viewpoint, and we obtain results relating the existence of large invariant
topological disks to the abundance of fixed points.Comment: Incorporates suggestions and corrections by the referees. To appear
in Inv. Mat
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