5,962 research outputs found

    Avalanche dynamics in fluid imbibition near the depinning transition

    Full text link
    We study avalanche dynamics and local activity of forced-flow imbibition fronts in disordered media. We focus on the front dynamics as the mean velocity vˉ\bar{v} of the interface is decreased and the pinning state is approached. Scaling arguments allow us to obtain the statistics of avalanche sizes and durations, which become power-law distributed due to the existence of a critical point at vˉ=0\bar{v}= 0. Results are compared with phase-field numerical simulations

    Time dependent couplings and crossover length scales in non-equilibrium surface roughening

    Get PDF
    We show that time dependent couplings may lead to nontrivial scaling properties of the surface fluctuations of the asymptotic regime in non-equilibrium kinetic roughening models . Three typical situations are studied. In the case of a crossover between two different rough regimes, the time-dependent coupling may result in anomalous scaling for scales above the crossover length. In a different setting, for a crossover from a rough to either a flat or damping regime, the time dependent crossover length may conspire to produce a rough surface, despite the most relevant term tends to flatten the surface. In addition, our analysis sheds light into an existing debate in the problem of spontaneous imbibition, where time dependent couplings naturally arise in theoretical models and experiments.Comment: Accepted for publication in Physical Review E (Rapid Comm.

    SPACE-TIME LAGS: SPECIFICATION STRATEGY IN SPATIAL REGRESSION MODELS

    Get PDF
    he purpose of this article is to analyse the dynamic trend of spatial dependence, which is not only contemporary but time-lagged in many socio-economic phenomena. Firstly, we show some of the commonly used exploratory spatial data analysis (ESDA) techniques and we propose other new ones, the exploratory space-time data analysis (ESTDA) that evaluates the instantaneity of spatial dependence. We also propose the space-time correlogram as an instrument for a better specification of spatial lag models, which should include both kind of spatial dependence. Some applications with economic data for Spanish provinces shed some light upon these issues.Spatial dependence, spatial diffusion, ESDA, correlogram, Spanish provinces

    The Pacific Alliance and the potential effects of a Trans-Pacific Economic Cooperation Agreement without the United States

    Get PDF
    This article analyzes the possible consequences of the entry into force of the Trans-Pacific Partnership Agreement (TPP) without the United States for the countries of the Pacific Alliance (PA). It develops a descriptive analysis of the evolution of trade between PA countries and TPP member countries during the period 1980-2015. Gravitational models are also estimated to empirically examine the determinants of trade flows in these countries. As a result, the paper shows that TPP may favor trade flows in PA countries, and that the withdrawal of the U.S. from TPP would not affect these trade flows.Este artículo analiza las posibles consecuencias, para los países de la Alianza del Pacífico (AP), de la entrada en vigor del Acuerdo de Asociación Transpacífico (TPP) sin Estados Unidos. Para ello, se desarrolla un análisis descriptivo de la evolución del comercio de los países de la AP con el resto de los países miembro del TPP durante el periodo 1980-2015. También se estiman modelos gravitacionales para examinar empíricamente los determinantes de los flujos comerciales de estos países. Se encuentra que el TPP puede favorecer los flujos comerciales de los países de la AP y que la salida de Estados Unidos del TPP no afectaría estos flujos comerciales

    Using DREADD to Examine the Role of Infralimbic Gq-coupled Receptors in Fear Acquisition

    Full text link
    Post-Traumatic Stress Disorder (PTSD) can develop after a person experiences a very traumatic event that produces a strong and long-lasting aversive memory. During any given year, approximately 8 million adults will suffer from PTSD. Existing treatments often fail to achieve a full extinction of the traumatic fear the patients re-experience. Consequently, how the brain processes and modulates fear memories continues to be an active area of research. The excitability of the infralimbic cortex (IL), a sub-region of the medial prefrontal cortex, is important for fear extinction. Previous studies done in our lab found that Gq-coupled receptors located in this region of the brain, specifically muscarinic and mGluR5 receptors play a critical role in the consolidation of extinction memory. However, their effect on the acquisition of fear is still unknown. Thus, the main purpose of this research is to determine whether the activation of Gq-coupled receptors in IL prior to the learning of fear affects fear memory. We hypothesized that stimulation of these receptors during fear conditioning would decrease acquired fear. To test this, we utilized a pharmacogenetic approach in the form of Designer Receptors Exclusively Activated by Designer Drugs (DREADD), which allow for controlled manipulation of the desired area in the brain using the selective agonist CNO. Adult male Sprague Dawley rats were surgically infused with a virus, which expressed a Gq-coupled DREADD. Three weeks later, the rats will be injected with CNO one hour prior to behavioral training and sacrificed for immunohistochemistry to examine neuronal activity

    Hyperglycemia and Diabetes in Myocardial Infarction

    Get PDF
    corecore