Stochastic theory of synchronization transitions in extended systems

We propose a general Langevin equation describing the universal properties of synchronization transitions in extended systems. By means of theoretical arguments and numerical simulations we show that the proposed equation exhibits, depending on parameter values: (i) a continuous transition in the bounded Kardar-Parisi-Zhang universality class, with a zero largest Lyapunov exponent at the critical point; (ii) a continuous transition in the directed percolation class, with a negative Lyapunov exponent, or (iii) a discontinuous transition (that is argued to be possibly just a transient effect). Cases (ii) and (iii) exhibit coexistence of synchronized and unsynchronized phases in a broad (fuzzy) region. This reproduces almost all of the reported features of synchronization transitions, providing a unified theoretical framework for the analysis of synchronization transitions in extended systems.Postprint (published version

Gestión del recurso hídrico a través de la economía doméstica de El Salvador: avances para lograr el ODS 6 "agua y saneamiento para todos", para el área Metropolitana de San Salvador (AMSS) 2008-2012.

El recurso hídrico representa para El Salvador y para todos los países del mundo un recurso estratégico y un bien nacional de carácter público con el cual se promueve la conservación de los ecosistemas junto con la diversidad biológica, la vida humana y el desarrollo de las sociedades. Reafirmando el derecho al agua; el pasado 22 de octubre de 2020 la Asamblea Legislativa aprobó la reforma a la Constitución de la República en los artículos 2 y 69. El objetivo es el de incluir al agua como un derecho humano al que todos tengan acceso así también de mejorar la institucionalidad del Estado, para crear y aprobar leyes que protejan los recursos naturales como lo es la Ley de agua. Además, en noviembre de 2010, en la resolución 64/292 la Asamblea General de las Naciones Unidas (ONU) reconoció explícitamente el derecho humano al agua y al saneamiento, reafirmando que un agua potable limpia y el saneamiento son esenciales para la realización de todos los derechos humanos. Dado que aún falta mucho por hacer a nivel nacional para dar cumplimiento a la parte jurídica en materia de gestión del Recurso Hídrico en favor del reconocimiento del derecho al agua y saneamiento para las comunidades que son afectadas por no tener acceso al agua potable; el Estado Salvadoreño debe trabajar por mejorar la institucional pública para lograr mayores avances en la aplicación de políticas y planes nacionales para dicha gestión, sustentando las acciones con una base legal y jurídica compuesta por un cuerpo normativo para la protección de los Recursos Naturales, así como para la distribución equitativa del agua y el tratamiento adecuado de esta. Asimismo, la población salvadoreña debe aumentar su participación para se cumplan las normativas y se generen políticas públicas en favor del Recurso Hídrico y el desarrollo sus habitantes

The universality class of absorbing phase transitions with a conserved field

We investigate the critical behavior of systems exhibiting a continuous absorbing phase transition in the presence of a conserved field coupled to the order parameter. The results obtained point out the existence of a new universality class of nonequilibrium phase transitions that characterizes a vast set of systems including conserved threshold transfer processes and stochastic sandpile models.Comment: RevTeX, 4 pages, 3 EPS figure

O mercado da identidade. O nativismo entre o colecionismo e as galerias durante o século XX

El presente artículo indagará en la presencia y circulación del nativismo en el mercado de arte argentino, entre 1910 y 1970. Para ello, realizaré una reconstrucción del contexto de surgimiento del nativismo como campo temático y, posteriormente, abordaré dos casos que se constituyen como paradigmas de su supervivencia: la trayectoria de Jorge Bermúdez (uno de los primeros artistas nativistas en alcanzar la consagración) y la obra de Antonio Berni (que circuló por el mercado durante la segunda mitad del siglo). Como hipótesis general, sostengo que la prolongada vida del nativismo se correspondió con una presencia constante de estas obras en colecciones y galerías privadas.This paper will inquire the presence and circulation of nativism in the Argentine art market between 1910 and 1970. To that end, I will first reconstruct the context of emergence of nativism as a thematic field and, later, I will address two cases which constitute paradigms of survival—the trajectory of Jorge Bermúdez (one of the first nativist artists to achieve success) and the work of Antonio Berni (which circulated through the market during the second half of the century). As a general hypothesis, I will maintain that the prolonged life of nativism was accompanied by a constant presence of these works in private collections and galleries.O presente artigo investigará a presença e a circulação do nativismo no mercado da arte argentino, entre 1910 e 1970. Para tanto, realizarei uma reconstrução do contexto de surgimento do nativismo como campo temático e, posteriormente, ocupar-me-ei de dois casos que se constituem como paradigmas da sua sobrevivência: a trajetória de Jorge Bermúdez (um dos primeiros artistas nativistas que alcançaram consagração) e a obra de Antonio Berni (que circulou pelo mercado durante a segunda metade do século). Como hipótese geral, sustento que a prolongada vida do nativismo corresponde a uma presença constante dessas obras em coleções e galerias privadas.Fil: Fasce, Pablo Javier. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentina. Universidad Nacional de San Martín. Centro de Investigaciones en Arte y Patrimonio. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Arte y Patrimonio; Argentin

Water Deficit and Heat Affect the Tolerance to High Illumination in Hibiscus Plants

This work studies the effects of water deficit and heat, as well as the involvement of chlororespiration and the ferredoxin-mediated cyclic pathway, on the tolerance of photosynthesis to high light intensity in Hibiscus rosa-sinensis plants. Drought and heat resulted in the down–regulation of photosynthetic linear electron transport in the leaves, although only a slight decrease in variable fluorescence (Fv)/maximal fluorescence (Fm) was observed, indicating that the chloroplast was protected by mechanisms that dissipate excess excitation energy to prevent damage to the photosynthetic apparatus. The incubation of leaves from unstressed plants under high light intensity resulted in an increase of the activity of electron donation by nicotinamide adenine dinucleotide phosphate (NADPH) and ferredoxin to plastoquinone, but no increase was observed in plants exposed to water deficit, suggesting that cyclic electron transport was stimulated by high light only in control plants. In contrast, the activities of the chlororespiration enzymes (NADH dehydrogenase (NDH) complex and plastid terminal oxidase (PTOX)) increased after incubation under high light intensity in leaves of the water deficit plants, but not in control plants, suggesting that chlororespiration was stimulated in stressed plants. The results indicate that the relative importance of chlororespiration and the cyclic electron pathway in the tolerance of photosynthesis to high illumination differs under stress conditions. When plants were not subjected to stress, the contribution of chlororespiration to photosynthetic electron flow regulation was not relevant, and another pathway, such as the ferredoxin-mediated cyclic pathway, was more important. However, when plants were subjected to water deficit and heat, chlororespiration was probably essential

Sustancias de crecimiento en la germinación de semillas de lechuga (Lactuca sativa L) / Romualdo Muñoz Girón ; director Francisco Sabater García.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. T.M.-113.CRAI CIENCIAS. DEPOSITO. T.D. 37

Water Deficit and Heat Affect the Tolerance to High Illumination in Hibiscus Plants

Abstract: This work studies the effects of water deficit and heat, as well as the involvement of chlororespiration and the ferredoxin-mediated cyclic pathway, on the tolerance of photosynthesis to high light intensity in Hibiscus rosa-sinensis plants. Drought and heat resulted in the down–regulation of photosynthetic linear electron transport in the leaves, although only a slight decrease in variable fluorescence (Fv)/maximal fluorescence (Fm) was observed, indicating that the chloroplast was protected by mechanisms that dissipate excess excitation energy to prevent damage to the photosynthetic apparatus. The incubation of leaves from unstressed plants under high light intensity resulted in an increase of the activity of electron donation by nicotinamide adenine dinucleotide phosphate (NADPH) and ferredoxin to plastoquinone, but no increase was observed in plants exposed to water deficit, suggesting that cyclic electron transport was stimulated by high light only in control plants. In contrast, the activities of the chlororespiration enzymes (NADH dehydrogenase (NDH) complex and plastid terminal oxidase (PTOX)) increased after incubation under high light intensity in leaves of the water deficit plants, but not in control plants, suggesting that chlororespiration was stimulated in stressed plants. Th

Nonlinear q-voter model

We introduce a nonlinear variant of the voter model, the q-voter model, in which q neighbors (with possible repetition) are consulted for a voter to change opinion. If the q neighbors agree, the voter takes their opinion; if they do not have a unanimous opinion, still a voter can flip its state with probability ε. We solve the model on a fully connected network (i.e., in mean field) and compute the exit probability as well as the average time to reach consensus by employing the backward Fokker-Planck formalism and scaling arguments. We analyze the results in the perspective of a recently proposed Langevin equation aimed at describing generic phase transitions in systems with two (Z2-symmetric) absorbing states. In particular, by deriving explicitly the coefficients of such a Langevin equation as a function of the microscopic flipping probabilities, we find that in mean field the q-voter model exhibits a disordered phase for high ε and an ordered one for low ε with three possible ways to go from one to the other: (i) a unique (generalized-voter-like) transition, (ii) a series of two consecutive transitions, one (Ising-like) in which the Z2 symmetry is broken and a separate one (in the directed-percolation class) in which the system falls into an absorbing state, and (iii) a series of two transitions, including an intermediate regime in which the final state depends on initial conditions. This third (so far unexplored) scenario, in which a type of ordering dynamics emerges, is rationalized and found to be specific of mean field, i.e., fluctuations are explicitly shown to wash it out in spatially extended systems