Competitive nucleation in reversible Probabilistic Cellular Automata

The problem of competitive nucleation in the framework of Probabilistic Cellular Automata is studied from the dynamical point of view. The dependence of the metastability scenario on the self--interaction is discussed. An intermediate metastable phase, made of two flip--flopping chessboard configurations, shows up depending on the ratio between the magnetic field and the self--interaction. A behavior similar to the one of the stochastic Blume--Capel model with Glauber dynamics is found

Perturbative analysis of disordered Ising models close to criticality

We consider a two-dimensional Ising model with random i.i.d. nearest-neighbor ferromagnetic couplings and no external magnetic field. We show that, if the probability of supercritical couplings is small enough, the system admits a convergent cluster expansion with probability one. The associated polymers are defined on a sequence of increasing scales; in particular the convergence of the above expansion implies the infinite differentiability of the free energy but not its analyticity. The basic tools in the proof are a general theory of graded cluster expansions and a stochastic domination of the disorder

Abrupt Convergence and Escape Behavior for Birth and Death Chains

We link two phenomena concerning the asymptotical behavior of stochastic processes: (i) abrupt convergence or cut-off phenomenon, and (ii) the escape behavior usually associated to exit from metastability. The former is characterized by convergence at asymptotically deterministic times, while the convergence times for the latter are exponentially distributed. We compare and study both phenomena for discrete-time birth-and-death chains on Z with drift towards zero. In particular, this includes energy-driven evolutions with energy functions in the form of a single well. Under suitable drift hypotheses, we show that there is both an abrupt convergence towards zero and escape behavior in the other direction. Furthermore, as the evolutions are reversible, the law of the final escape trajectory coincides with the time reverse of the law of cut-off paths. Thus, for evolutions defined by one-dimensional energy wells with sufficiently steep walls, cut-off and escape behavior are related by time inversion.Comment: 2 figure

Análisis de Ciclo de Vida para el ecodiseño del sistema Intemper TF de cubierta ecológica aljibe

The construction industry is one of the less sustainable activities on the planet: with a consumption of 40% of the materials entering the global economy and the generation of 40–50% of the global output of greenhouse gases. The biggest environmental impact caused by buildings is generated during their use phase due to the energy consumption for thermal conditioning. Addition of green elements to buildings is used to improve energy efficiency of buildings. In this study Life Cycle Assessment (LCA) methodology has been applied to quantify the environmental impact of the green roofs materials to analyze its environmental profile. The identification of hot spots of the system permits an ecodesign strategy that effectively reduces environmental burdens associated with roof construction, optimizing the environmental performance. The results identify the high environmental impact associated to the structure, the important contribution of the felt wick irrigation system and the extruded polystyrene thermal insulation.El sector de la construcción representa una de las actividades menos sostenibles del planeta: consume el 40% de los materiales de la economía global y genera el 40-50% de las emisiones de gases de efecto invernadero. El mayor impacto ambiental de los edificios se genera durante su fase de uso, debido al gasto energético de su acondicionamiento térmico. El uso de elementos vegetales es una de las estrategias empleadas para aumentar la eficiencia energética. En este trabajo se ha empleado la metodología de Análisis de Ciclo de Vida (ACV) para cuantificar el impacto ambiental de los materiales de la cubierta vegetal. Se han identificado los puntos críticos del sistema para establecer una estrategia de ecodiseño y reducir eficazmente las cargas ambientales. Los resultados obtenidos muestran la importancia del impacto ambiental del soporte estructural, la elevada contribución de la mecha de riego de fieltro y del aislamiento de poliestireno extrudido

Metastability and small eigenvalues in Markov chains

In this letter we announce rigorous results that elucidate the relation between metastable states and low-lying eigenvalues in Markov chains in a much more general setting and with considerable greater precision as was so far available. This includes a sharp uncertainty principle relating all low-lying eigenvalues to mean times of metastable transitions, a relation between the support of eigenfunctions and the attractor of a metastable state, and sharp estimates on the convergence of probability distribution of the metastable transition times to the exponential distribution.Comment: 5pp, AMSTe

Aging of malbec wines from Mendoza and California: Evolution of volatile composition

Background and goals The search for strategies to improve the quality of Argentine Malbec wines has led to experimentation with production of wines that achieve superior sensory properties after prolonged bottle aging. During aging, a series of complex oxidation-reduction and polymerization reactions occur. These reactions, responsible for changing the sensory aspects of wines, can be influenced by a variety of factors (terroir, winemaking practices, storage conditions, etc.). Thus, understanding the chemical processes that take place during bottle aging could significantly impact the enology industry. This work evaluates the evolution of aromatic profiles over time in Malbec wines from Mendoza and California. Methods and key findings Wines from Mendoza and California were obtained under standardized conditions. Determination of volatile profiles was carried out on young wines by gas chromatography-mass spectrometry and, subsequently, after seven years of aging. The effect of time and region on volatile profiles was investigated. The aging time showed a significant effect on the aromatic composition. While the profiles obtained after seven years were less diverse than at bottling, they retained a significant number of desirable volatile compounds. Additionally, the volatile profiles of the aged wines still permitted differentiation of samples by region of origin. Conclusions and significance The information obtained enabled us to assess the evolution of aromatic profiles during bottle aging of Malbec wines from Mendoza and California, and could be useful in decision-making regarding the blending, marketing, and storage of these wines.Fil: Pellegrino Vidal, Rocio. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina. Catena Institute Of Wine.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Boulton, Roger B.. University of California at Davis; Estados UnidosFil: Olivieri, Alejandro Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Buscema, Fernando. Catena Institute Of Wine.; Argentin

The P-glycoprotein Inhibitor GF120918 Modulates Ca2+-Dependent Processes and Lipid Metabolism in Toxoplasma Gondii

Up-regulation of the membrane-bound efflux pump P-glycoprotein (P-gp) is associated with the phenomenon of multidrug-resistance in pathogenic organisms, including protozoan parasites. In addition, P-gp plays a role in normal physiological processes, however our understanding of these P-gp functions remains limited. In this study we investigated the effects of the P-gp inhibitor GF120918 in Toxoplasma gondii, a model apicomplexan parasite and an important human pathogen. We found that GF120918 treatment severely inhibited parasite invasion and replication. Further analyses of the molecular mechanisms involved revealed that the P-gp inhibitor modulated parasite motility, microneme secretion and egress from the host cell, all cellular processes known to depend on Ca2+ signaling in the parasite. In support of a potential role of P-gp in Ca2+-mediated processes, immunoelectron and fluorescence microscopy showed that T. gondii P-gp was localized in acidocalcisomes, the major Ca2+ storage in the parasite, at the plasma membrane, and in the intravacuolar tubular network. In addition, metabolic labeling of extracellular parasites revealed that inhibition or down-regulation of T. gondii P-gp resulted in aberrant lipid synthesis. These results suggest a crucial role of T. gondii P-gp in essential processes of the parasite biology and further validate the potential of P-gp activity as a target for drug development

Calibration Measurements of the LHC Beam Dumping System Extraction Kicker Magnets

The LHC beam dumping system must protect the LHC machine from damage by reliably and safely extracting and absorbing the circulating beams when requested. Two sets of 15 extraction kicker magnets form the main active part of this system. They have been produced, tested and calibrated by measuring the integrated magnetic field and the magnet current at different beam energies. The calibration data have been analysed, and the critical parameters are compared with the specifications. Implications for the configuration, control and operation of the beam dumping system are discussed

High Temperature Expansions and Dynamical Systems

We develop a resummed high-temperature expansion for lattice spin systems with long range interactions, in models where the free energy is not, in general, analytic. We establish uniqueness of the Gibbs state and exponential decay of the correlation functions. Then, we apply this expansion to the Perron-Frobenius operator of weakly coupled map lattices.Comment: 33 pages, Latex; [email protected]; [email protected]

Feasibility assessment of reclaimed wastewater reuse in agriculture: how we do it

The growing interest towards wastewater (WW) reuse as alternative irrigation source is raised by the worldwide concern on water shortages and enhanced by the new European Directive on water reuse minimum requirements. In this perspective, water utilities and decision makers would benefit from a methodology to evaluate and encourage safe and efficient agricultural WW reuse practices. In this work, we propose a novel approach to identify criteria for assessing and prioritizing WW treatment plants (WWTPs) suitability for WW reuse practices implementation. The developed methodology, coupling WWTPs’ characteristics (i.e., flowrate and effluent quality) and features of the local territory (i.e., cultivated crops and climate), is able to quantify the economic savings, in terms of water and nutrients, and avoided environmental impacts, that could be fulfilled from WW reuse, and which WWTPs and territories to prioritize in its implementation