5,234 research outputs found

    Large Amplitude Harmonic Driving of Highly Coherent Flux Qubits

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    The device for the Josephson flux qubit (DJFQ) can be considered as a solid state artificial atom with multiple energy levels. When a large amplitude harmonic excitation is applied to the system, transitions at the energy levels avoided crossings produce visible changes in the qubit population over many driven periods that are accompanied by a rich pattern of interference phenomena. We present a Floquet treatment of the periodically time-dependent Schr\"odinger equation of the strongly driven qubit beyond the standard two levels approach. For low amplitudes, the average probability of a given sign of the persistent current qubit exhibits, as a function of the static flux detuning and the driving amplitude, Landau-Zener-St\"uckelberg interference patterns that evolve into complex diamond-like patterns for large amplitudes. In the case of highly coherent flux qubits we find that the higher order diamonds can not be simply described relying on a two-level approximations. In addition we propose a new spectroscopic method based on starting the system in the first excited state instead of in the ground state, which can give further information on the energy level spectrum and dynamics in the case of highly coherent flux qubits. We compare our numerical results with recent experiments that perform amplitude spectroscopy to probe the energy spectrum of the artificial atom.Comment: 12 Pages and 12 Figures Phys. Rev. B (in press

    Completeness in the Mackey topology by norming subspaces

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    [EN] We study the class of Banach spaces X such that the locally convex space (X, mu(X,Y)) is complete for every norming and norm-closed subspace Y subset of X*, where mu(X, Y) denotes the Mackey topology on X associated to the dual pair . Such Banach spaces are called fully Mackey complete. We show that fully Mackey completeness is implied by Efremov's property (epsilon) and, on the other hand, it prevents the existence of subspaces isomorphic to l(1)(omega(1)). This extends previous results by Guirao et al. (2017) [9] and Bonet and Cascales (2010) [3]. Further examples of Banach spaces which are not fully Mackey complete are exhibited, like C[0, omega(1)] and the long James space J(omega(1)). Finally, by assuming the Continuum Hypothesis, we construct a Banach space with w*-sequential dual unit ball which is not fully Mackey complete. A key role in our discussion is played by the (at least formally) smaller class of Banach spaces X such that (Y, w*) has the Mazur property for every norming and norm-closed subspace Y subset of X*. (C) 2019 Elsevier Inc. All rights reserved.The authors wish to thank A. Aviles for valuable discussions on the topic of this paper. They are also grateful to the referee for his/her comments and suggestions. A.J. Guirao was supported by projects MTM2017-83262-C2-1-P (AEI/FEDER, UE) and 19368/PI/14 (Fundacion Seneca). G. Martinez-Cervantes and J. Rodriguez were supported by projects MTM2014-54182-P and MTM2017-86182-P (AEI/FEDER, UE) and 19275/PI/14 (Fundacion Seneca).Guirao Sánchez, AJ.; Martínez-Cervantes, G.; Rodríguez Ruiz, J. (2019). Completeness in the Mackey topology by norming subspaces. Journal of Mathematical Analysis and Applications. 478(2):776-789. https://doi.org/10.1016/j.jmaa.2019.05.054S776789478

    Composition variation of the essential oil from Ocimum basilicum L. cv. Genovese Gigante in response to Glomus intraradices and mild water stress at different stages of growth

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    In this study, a factorial experiment was carried out to investigate the effect of AMF (arbuscular mycorrhizal fungi) and water stress on the quality of fresh plants (through the analysis of essential oil composition) and also on the morphological characteristics (in terms of biomass) of basil (Ocimum basilicum L. cv. Genovese Gigante). The factors included an arbuscular mycorrhizal fungus inoculation (Glomus intraradices), irrigation level (mild water stress, 60% Field capacity) and the interaction of both AMF and water stress. In addition, the effects of harvesting at two different developmental stages were assessed with respect to the plants tolerance to abiotic stress and the quality of the fresh plant. The main essential oil (EO) constituents for this cultivar were eugenol, which varied between 7.1 and 50.8%, and linalool, 17.0–54.7%, in all the samples. The highest relative amount of eugenol (50.8%) was obtained during the vegetative stage in plants under water stress whereas samples from the control presented 16.2% for this compound. The samples which were significantly different from the control samples were the WS (water stress) samples from the vegetative stage. Additionally, this study suggests that AMF plants offset the adverse effect of water stress. In this context, and since the interaction of AMF and water stress did not significantly change the fresh plant quality, i.e. the essential oil profile in both stages of development, it is worthwhile considering this method of production. Finally, this experiment permitted an understanding of the stressor thresholds of the species used and also that, compensatory responses occur at different time scales, including between generations and also during development (developmental plasticity)info:eu-repo/semantics/publishedVersio

    Prosomeric Hypothalamic Distribution of Tyrosine Hydroxylase Positive Cells in Adolescent Rats

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    This study was funded by the Spanish Ministry of Science, Innovation, and Universities (MCIU), State Research Agency (AEI), and European Regional Development Fund (FEDER); PGC2018-098229-B-100 to JF and by Seneca Foundation (19904/GERM/15).Most of the studies on neurochemical mapping, connectivity, and physiology in the hypothalamic region were carried out in rats and under the columnar morphologic paradigm. According to the columnar model, the entire hypothalamic region lies ventrally within the diencephalon, which includes preoptic, anterior, tuberal, and mamillary anteroposterior regions, and sometimes identifying dorsal, intermediate, and ventral hypothalamic partitions. This model is weak in providing little or no experimentally corroborated causal explanation of such subdivisions. In contrast, the modern prosomeric model uses different axial assumptions based on the parallel courses of the brain floor, alar-basal boundary, and brain roof (all causally explained). This model also postulates that the hypothalamus and telencephalon jointly form the secondary prosencephalon, separately from and rostral to the diencephalon proper. The hypothalamus is divided into two neuromeric (transverse) parts called peduncular and terminal hypothalamus (PHy and THy). The classic anteroposterior (AP) divisions of the columnar hypothalamus are rather seen as dorsoventral subdivisions of the hypothalamic alar and basal plates. In this study, we offered a prosomeric immunohistochemical mapping in the rat of hypothalamic cells expressing tyrosine hydroxylase (TH), which is the enzyme that catalyzes the conversion of L-tyrosine to levodopa (L-DOPA) and a precursor of dopamine. This mapping was also combined with markers for diverse hypothalamic nuclei [agouti-related peptide (Agrp), arginine vasopressin (Avp), cocaine and amphetamine-regulated transcript (Cart), corticotropin releasing Hormone (Crh), melanin concentrating hormone (Mch), neuropeptide Y (Npy), oxytocin/neurophysin I (Oxt), proopiomelanocortin (Pomc), somatostatin (Sst), tyrosine hidroxilase (Th), and thyrotropin releasing hormone (Trh)]. TH-positive cells are particularly abundant within the periventricular stratum of the paraventricular and subparaventricular alar domains. In the tuberal region, most labeled cells are found in the acroterminal arcuate nucleus and in the terminal periventricular stratum. The dorsal retrotuberal region (PHy) contains the A13 cell group of TH-positive cells. In addition, some TH cells appear in the perimamillary and retromamillary regions. The prosomeric model proved useful for determining the precise location of TH-positive cells relative to possible origins of morphogenetic signals, thus aiding potential causal explanation of position-related specification of this hypothalamic cell type.State Research Agency (AEI)European Commission PGC2018-098229-B-100Fundacion Seneca 19904/GERM/15Spanish Governmen

    Hyperbolic reflections as fundamental building blocks for multilayer optics

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    We reelaborate on the basic properties of lossless multilayers by using bilinear transformations. We study some interesting properties of the multilayer transfer function in the unit disk, showing that hyperbolic geometry turns out to be an essential tool for understanding multilayer action. We use a simple trace criterion to classify multilayers into three classes that represent rotations, translations, or parallel displacements. Moreover, we show that these three actions can be decomposed as a product of two reflections in hyperbolic lines. Therefore, we conclude that hyperbolic reflections can be considered as the basic pieces for a deeper understanding of multilayer optics.Comment: 7 pages, 7 figures, accepted for publication in J. Opt. Soc. Am.

    Mappings between dendroids (fans) that (does not) preserve (non)contractibility.

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    J. J. Charatonik formuló en 1991 el siguiente problema: ¿Qué funciones preservan contractibilidad (no contractibilidad) de dendroides? Por otro lado, J. J. Charatonik, W. J. Charatonik y S. Miklos en 1990 hicieron las siguientes preguntas: ¿Qué tipo de funciones confluentes preservan contractibilidad de abanicos? y ¿Qué tipo de funciones confluentes preservan no contractibilidad de abanicos?En este artículo daremos algunas respuestas parciales a estas preguntas. Adicionalmente, consideramos estas preguntas con otras familias de funciones.J. J. Charatonik formulated in 1991 the following problem: What are all mappings that preserve contractibility (noncontractibility) of dendroids? On the other hand, J. J. Charatonik, W. J. Charatonik, and S. Miklos asked in 1990 the following questions (among others related to contractibility): What kinds of confluent mappings preserve contractibility of fans? And what kinds of confluent mappings preserve non contractibility of fans?In this paper, we will show some partial answers to these questions. Additionally, we will consider these questions with other kinds of families of mappings

    Vegetación acuática y helofítica del Sistema Ibérico septentrional, centro de España

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    Vegetación acuática y helofítica del Sistema Ibérico septentrional, centro de España. En este trabajo, se han reconocido 11 asociaciones y 4 comunidades pertenecientes a las clases fitosociológicas Potametea y Phragmito-Magnocaricetea. El Sistema Ibérico septentrional constituye un límite meridional para comunidades de óptimo centro-europeo -Caricetum rostratae, Caricetum vesicariae y Comunidad de Sparganium emersum-, así como un límite oriental para comunidades de óptimo atlántico -Ranunculetum omiophylli, Galio broteriani-Caricetum broterianae, Glycerio declinatae-Eleocharitetum-palustris, Glycerio declinatae-Oenanthetum crocatae y Oenantho crocatae-Phalaridetum arundinaceae-

    On financial frictions and firm market power

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    Construimos un modelo de equilibrio general estático con empresas monopolísticamente competitivas que toman prestados fondos de bancos competitivos en una economía sujeta a restricciones fi nancieras. Estas fricciones son debidas a la imposibilidad de verifi car tanto los benefi cios de las empresas como el esfuerzo de sus gestores. El poder de mercado tiene dos efectos contrapuestos. Por un lado, las empresas marcan sus precios por encima del coste marginal y la producción resultante es inferior a la que se obtendría en competencia perfecta. Por otro, debido al incremento en la rentabilidad de las empresas, el poder de mercado reduce el impacto de las fricciones financieras. El resultado de la interacción de estos dos efectos es ambiguo. Este trabajo muestra que, ceteris paribus, existe un nivel óptimo positivo de poder de mercado que maximiza el bienestar. Este nivel aumenta con el riesgo moral y disminuye con la efi ciencia del proceso de liquidación de las empresas en caso de quiebra.We build a static general-equilibrium model with monopolistically competitive fi rms that borrow funds from competitive banks in an economy subject to fi nancial frictions. These frictions are due to non verifi ability of both ex post fi rm returns and managerial effort. Market power has opposing effects. On one side, fi rms’ pricing over marginal cost reduces output compared to perfect competition. On the other, by increasing fi rms’ profi tability, market power reduces the impact of fi nancial frictions. The resulting tradeoff is ambiguous. We show that, other things equal, there exists an optimal positive level of market power that maximizes welfare. Such optimal degree of market power increases with moral hazard and decreases with the effi ciency of fi rm liquidation following bankruptcy

    Estudio comparativo del blanqueo de la lana por los procedimientos de inmersión e impregnación-vaporizado.

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    El presente estudio ha tenido por objeto el conocimiento de la mejora del blanco experimentada por dos lanas de diferente coloración cuando se las somete a un blanqueo mixto continuo en una instalación piloto de tipo industrial, efectuando el blanqueo oxidante por el sistema de impregnación-vaporizado y el reductor en los compartimentos de la máquina destinados a tratamientos de lavado o posteriores. Los resultados obtenidos se han comparado con los que se derivan de la aplicación del blanqueo mixto discontinuo convencional, deduciéndose que el blanqueo mixto continuo proporciona blancos iguales o algo inferiores, según el grado de coloración de la lana inicial, degradaciones químicas inferiores, y evidentes ahorros en el consumo de productos, agua y energía térmica.This paper deals with the improvement of whiteness achieved by two kinds of wool, having different colouration, when they are submitted to a continuous and combined bleaching in an industrial pilot unit. The oxidizing bleaching is applied according to the pad-steam method and the reducing one takes place in the boxes of the machine provided for washing or post-treatments. The results found have been compared to the resulting ones from the application of a conventional noncontinuous and combined bleaching: the former provides similar or somewhat lower whiteness, according to the colouration degree of the initial wool, lower chemical degradation and an obvious economy in the consumption of water, heat power and chemicals.La présente étude a eu pour objet la connaissance de l'amélioration du blanc expérimentée par deux laines de différente coloration lorqu'on les soumet à un blanchissage mixte continu dans unes installation pilote industrielle en effectuant le blanchissage oxydant par le systeme imprégnation-vaporisage et celui réducteur dans les compartiments de la machine destinés a des traitements de lavage ou postérieurs. On a comparé les résultats obtenus avec ceux qui dérivent de l'application du blanchissage mixte discontinu conventionnel; on a pu en déduire que dans le blanchissage mixte continu les blancs sont égaux ou un peu inférieurs á ceux du blanchissage mixte discontinu, selon le degré de coloration de la laine initial, que les dégradations chimiques sont inférieures et que l'on réalise des économies évidentes de consommation de produits, d'eau et d'énergie thermique et électrique.Peer Reviewe
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