1,125 research outputs found
Photon creation in a spherical oscillating cavity
We study the photon creation inside a perfectly conducting, spherical
oscillating cavity. The electromagnetic field inside the cavity is described by
means of two scalar fields which satisfy Dirichlet and (generalized) Neumann
boundary conditions. As a preliminary step, we analyze the dynamical Casimir
effect for both scalar fields. We then consider the full electromagnetic case.
The conservation of angular momentum of the electromagnetic field is also
discussed, showing that photons inside the cavity are created in singlet
states.Comment: 14 pages, no figure
Determination of the influence of specific building regulations in smart buildings
The automation of domestic services began to be implemented in buildings since the late nineteenth century, and today we are used to terms like ‘intelligent buildings’, ‘digital home’ or ‘domotic buildings’. These concepts tell us about constructions which integrate
new technologies in order to improve comfort, optimize energy consumption or enhance the security of users. In conjunction, building regulations have been updated to suit the needs of society and to regulate these new facilities in such structures. However, we are not always
sure about how far, from the quantitative or qualitative point of view, legislation should
regulate certain aspects of the building activity. Consequently, content analysis is adopted in
this research to determine the influence of building regulations in the implementation of
new technologies in the construction process. This study includes the analysis of different
European regulations, the collection and documentation of such guidelines that have been
established and a study of the impact that all of these have had in the way we start thinking an architectural project. The achievements of the research could be explained in terms of the regulatory requirements that must be taken into account in order to achieve a successful implementation of a home automation system, and the key finding has been the confirmation of how the design of smart buildings may be promoted through specific regulatory requirements while other factors, such as the global economic situation, do not seem to affect directly the rate of penetration of home automation in construction
Triadic percolation induces dynamical topological patterns in higher-order networks
Triadic interactions are higher-order interactions which occur when a set of nodes affects the interaction between two other nodes. Examples of triadic interactions are present in the brain when glia modulate the synaptic signals among neuron pairs or when interneuron axo-axonic synapses enable presynaptic inhibition and facilitation, and in ecosystems when one or more species can affect the interaction among two other species. On random graphs, triadic percolation has been recently shown to turn percolation into a fully fledged dynamical process in which the size of the giant component undergoes a route to chaos. However, in many real cases, triadic interactions are local and occur on spatially embedded networks. Here, we show that triadic interactions in spatial networks induce a very complex spatio-temporal modulation of the giant component which gives rise to triadic percolation patterns with significantly different topology. We classify the observed patterns (stripes, octopus, and small clusters) with topological data analysis and we assess their information content (entropy and complexity). Moreover, we illustrate the multistability of the dynamics of the triadic percolation patterns, and we provide a comprehensive phase diagram of the model. These results open new perspectives in percolation as they demonstrate that in presence of spatial triadic interactions, the giant component can acquire a time-varying topology. Hence, this work provides a theoretical framework that can be applied to model realistic scenarios in which the giant component is time dependent as in neuroscience
Best experienced payoff dynamics and cooperation in the centipede game
We study population game dynamics under which each revising agent tests each
of his strategies a fixed number of times, with each play of each strategy being
against a newly drawn opponent, and chooses the strategy whose total payoff was
highest. In the centipede game, these best experienced payoff dynamics lead to cooperative
play. When strategies are tested once, play at the almost globally stable
state is concentrated on the last few nodes of the game, with the proportions of
agents playing each strategy being largely independent of the length of the game.
Testing strategies many times leads to cyclical play.U.S. National Science Foundation (Grants SES-1458992 and SES- 1728853), the U.S. Army Research Office (Grants W911NF-17-1-0134 MSN201957), Project ECO2017-83147- C2-2-P (MINECO/AEI/FEDER, UE), and the Spanish Ministerio de Educación, Cultura, y Deporte (Grants PRX15/00362 and PRX16/00048
EvoDyn-3s: A Mathematica computable document to analyze evolutionary dynamics in 3-strategy games
EvoDyn-3s generates phase portraits of evolutionary dynamics, as well as data for the analysis of their
equilibria. The considered evolutionary dynamics are ordinary differential equations based on adaptive
processes taking place in a population of players who are randomly and repeatedly matched in couples to
play a 2-player symmetric normal-form game with three strategies. EvoDyn-3s calculates the rest points of
the dynamics using exact arithmetic, and represents them. It also provides the eigenvalues of the Jacobian
of the dynamics at the isolated rest points, which are useful to evaluate their local stability. The user only
needs to specify the 3 × 3 payoff matrix of the game and choose the dynamics.Spanish Ministry of Science and Innovation ’s project ECO2017-83147-C2-2-P (MINECO/AEI/FEDER, UE
PROP1 triggers epithelial-mesenchymal transition-like process in pituitary stem cells
Mutations in PROP1 are the most common cause of hypopituitarism in humans; therefore, unraveling its mechanism of action is highly relevant from a therapeutic perspective. Our current understanding of the role of PROP1 in the pituitary gland is limited to the repression and activation of the pituitary transcription factor genes Hesx1 and Pou1f1, respectively. To elucidate the comprehensive PROP1-dependent gene regulatory network, we conducted genome wide analysis of PROP1 DNA binding and effects on gene expression in mutant mice, mouse isolated stem cells and engineered mouse cell lines. We determined that PROP1 is essential for stimulating stem cells to undergo an epithelial to mesenchymal transition-like process necessary for cell migration and differentiation. Genomic profiling reveals that PROP1 binds to genes expressed in epithelial cells like Claudin 23, and to EMT inducer genes like Zeb2, Notch2 and Gli2. Zeb2 activation appears to be a key step in the EMT process. Our findings identify PROP1 as a central transcriptional component of pituitary stem cell differentiation.Fil: Pérez Millán, María Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Brinkmeier, Michelle. University of Michigan; Estados UnidosFil: Mortensen, Amanda H. University of Michigan; Estados UnidosFil: Camper, Sally. University of Michigan; Estados Unido
Cinemática rotacional del cabalgamiento basal surpirenaico en las Sierras Exteriores Aragonesas: Datos magnetotectónicos
The magnetotectonic analysis of 32 sites located along the External Sierras (mainly in Middle Eocene marls) shows the primary character of the magnetisation and pennits the differences between the paleovectors obtained to be interpreted as a result of the rotational kinematics of the southpyrenean floor thrust in the study area. The constancy of the directions of the defined unblocking intervals (300"-425°C for the thermal treatment) and the homogeneity of the magnetic carriers (these were always low coercitivity phases, probably sulphides andlor magnetite) prove the stability of the magnetisation. On the other hand, the primary character of the magnetisation (Middle Eocene) can be demonstrated by: a) the constancy of the magnetic inclination (47.3 +/- 1.7) and its similarity with the reference direction; b) the occurrence of reversals, and the positive result of the fold-test made in the Pico del Águila anticline; c) the consistency between the reference direction (DEC = 005", INC = 51°, a95=6 ") and the direction obtained for the authocthonous footwall (DEC = 005", INC = 38", a95= 8") which crops out in the western sector of the Sierras Exteriores thrust front. The interpretation of the paleomagnetic data within the External Sierras structural framework clearly shows that the kinematics of individual thrust sheets involves a clockwise component, at least during a period of their evolution. The maximum rotation values were found in the western and central sectors (42" and 30" respectively). The age of the rotation decreases towards the west along with the age of deformation of the cover rocks. Starting in late Priabonian the kinematics of the thrust front resulted in a lack of rotation in the central sector of the Sierras, while the western sector undenvent a clockwise rotation. The differential movement between both sectors gave rise to the development or reactivation of structures (i. e. Rasal-Anzáñigo anticlines) that articulated the deformation of adjacent zones with different rotational components
Rotational kinematics of the southpyrenean basal thrust at the Sierras Exteriores Aragonesas: Magnetotectonic data
[ES] El estudio magnetotectónico de 32 estaciones localizadas, principalmente, en las margas de la formación Arguis a lo largo de las
Sierras Exteriores Aragonesas (Pirineo Suroccidental) nos ha permitido caracterizar la estabilidad y el carácter primario de la magnetización
registrada por estas rocas e interpretar las diferencias con el campo de referencia (Iberia estable) en términos de cinemática rotacional
asociada al cabalgamiento basal surpirenaico en este sector.
La estabilidad de la magnetización se fundamenta en la constancia de los intervalos de definición de las direcciones (300" - 425°C
en el tratamiento térmico) y en la homogeneidad de los portadores magnéticos en las estaciones estudiadas (que siempre fueron fases
de baja coercitividad, probablemente sulfuros y10 magnetita). Por otra parte, se puede demostrar que dicha magnetización se adquirió en
el momento del depósito de las rocas (Eoceno medio) por varios motivos; la constancia de la inclinación magnética (47,3" +/- 1,7") y su
similitud con la dirección de referencia; la existencia de inversiones y el test del pliegue positivo realizado con las estaciones del anticlinal
del Pico del Águila; así como la congruencia entre la dirección de referencia (DEC=005", INC=51°, q5=6') y la calculada en la
zona autóctona del sector occidental de las Sierras (DEC=005', INC=38', ag5=8 ").
La interpretación de los datos paleomagnéticos en el contexto de la estructura deja patente la componente rotacional horaria de los
cabalgamientos asociada a la formación de las Sierras Exteriores, observándose valores máximos de 42' en el sector occidental y de 30"
en el central. Asimismo, la edad de dicha rotación parece migrar hacia el W (simultánea y anterior al depósito de la Fm. margas de Arguis,
Priaboniense, en el sector central y simultánea al depósito de la Fm. Campodarbe, Sannoisiense-Stampiense, en el sector occidental)
y se puede afirmar que ha habido rotación diferencial entre sectores adyacentes. Para explicar la no acumulación de las rotaciones es necesaria la existencia de estructuras de articulación que separarían zonas con diferente componente rotacional, como parece ocurrir
en los anticlinales de Rasa1 y Anzañigo.[EN] The magnetotectonic analysis of 32 sites located along the External Sierras (mainly in Middle Eocene marls) shows the primary character
of the magnetisation and pennits the differences between the paleovectors obtained to be interpreted as a result of the rotational
kinematics of the southpyrenean floor thrust in the study area.
The constancy of the directions of the defined unblocking intervals (300"-425°C for the thermal treatment) and the homogeneity of
the magnetic carriers (these were always low coercitivity phases, probably sulphides andlor magnetite) prove the stability of the magnetisation.
On the other hand, the primary character of the magnetisation (Middle Eocene) can be demonstrated by: a) the constancy of
the magnetic inclination (47.3 +/- 1.7) and its similarity with the reference direction; b) the occurrence of reversals, and the positive result
of the fold-test made in the Pico del Águila anticline; c) the consistency between the reference direction (DEC = 005", INC = 51°,
a95=6 ") and the direction obtained for the authocthonous footwall (DEC = 005", INC = 38", a95= 8") which crops out in the western
sector of the Sierras Exteriores thrust front.
The interpretation of the paleomagnetic data within the External Sierras structural framework clearly shows that the kinematics of
individual thrust sheets involves a clockwise component, at least during a period of their evolution. The maximum rotation values were
found in the western and central sectors (42" and 30" respectively). The age of the rotation decreases towards the west along with the
age of deformation of the cover rocks. Starting in late Priabonian the kinematics of the thrust front resulted in a lack of rotation in the
central sector of the Sierras, while the western sector undenvent a clockwise rotation. The differential movement between both sectors
gave rise to the development or reactivation of structures (i. e. Rasal-Anzáñigo anticlines) that articulated the deformation of adjacent
zones with different rotational components.lEste trabajo ha sido financiado por una beca de la Institución
Fernando el Católico (Dip. Prov. de Zaragoza) durante 1993 y
una beca de Formación de Profesorado Universitario (M.E.C.)
1996- concedidas al primero de los firmantes, una beca CONA1
(DGA') concedida al segundo firmante, así como por los proyectos
PB93-1218 DGICYT y una acción integrada Hispano-Austríaca
(HU1995-0023). Ana Gómez del laboratorio de Paleomagnetismo
de ICT "Jaume Almera" CSIC se encargó de buena
parte de los análisis preliminares durante 1992. Carlos Sabariego
(Saba) y Tomás Arauzo colaboraron en los muestreos. Todas
las proyecciones estereográficas se realizaron utilizando el programa
Stereonet (v. 4.9.5) de R. Allmendinger, a quien estamos
muy agradecidos por su generosidad. La revisión de Jaume Dinarés
fue especialmente provechosa.Peer reviewe
Temperature dependence of antiferromagnetic susceptibility in ferritin
We show that antiferromagnetic susceptibility in ferritin increases with
temperature between 4.2 K and 180 K (i. e. below the N\'{e}el temperature) when
taken as the derivative of the magnetization at high fields (
Oe). This behavior contrasts with the decrease in temperature previously found,
where the susceptibility was determined at lower fields ( Oe). At
high fields (up to Oe) the temperature dependence of the
antiferromagnetic susceptibility in ferritin nanoparticles approaches the
normal behavior of bulk antiferromagnets and nanoparticles considering
superantiferromagnetism, this latter leading to a better agreement at high
field and low temperature. The contrast with the previous results is due to the
insufficient field range used ( Oe), not enough to saturate the
ferritin uncompensated moment.Comment: 7 pages, 7 figures, accepted in Phys. Rev.
Large quantum nonlinear dynamic susceptibility of single-molecule magnets
The nonlinear dynamical response of Mn single-molecule magnets is
experimentally found to be very large, quite insensitive to the spin-lattice
coupling constant, and displaying peaks reversed with respect to classical
superparamagnets. It is shown that these features are caused by the strong
field dependence of the relaxation rate due to the detuning of energy levels
between which tunneling takes place. The nonlinear susceptibility technique,
previously overlooked, is thus proposed as a privileged probe to ascertain the
occurrence of quantum effects in mesoscopic magnetic systems.Comment: 4 pages, 4 figure
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