Pullback attractors for a singularly nonautonomous plate equation

We consider the family of singularly nonautonomous plate equation with structural damping $$u_{tt} + a(t,x)u_{t} + (- \Delta) u_{t} + (-\Delta)^{2} u + \lambda u = f(u),$$ in a bounded domain $\Omega \subset \R^n$, with Navier boundary conditions. When the nonlinearity $f$ is dissipative we show that this problem is globally well posed in $H^2_0(\Omega) \times L^2(\Omega)$ and has a family of pullback attractors which is upper-semicontinuous under small perturbations of the damping $a$

Um dândi nos trópicos: esporte e educação do corpo nas crônicas de Paulo Barreto (João do Rio)

O presente artigo teve como objetivo analisar como o esporte e os processos de educação do corpo se manifestaram nas crônicas de Paulo Barreto, mais conhecido como João do Rio. As fontes selecionadas foram as crônicas publicadas pelo literato até 1921, ano de sua morte, cujo assunto primário ou secundário tenha sido o esporte. A palavra se mostrou presente na obra do escritor, porém se manifestou de uma forma ampla, ora repercutindo pontos positivos ora enfatizando aspectos negativos, mas como característica comum as diversas maneiras de educação do corpo. A título de conclusão, aponta-se que o esporte foi acionado pelo autor para representar as facetas existentes no seio da sociedade carioca e que nessas representações estavam evidentes modos de vida que possuíam alguns elementos educacionais relativos ao corpo

The decidability of a fragment of BB′IW-logic

AbstractDespite its simple formulation, the decidability of the logic BB′IW has remained an open problem. We present here a decision procedure for a fragment of it, called the arity-1 formulas.The decidability proof is based on a representation of formulas called formula-trees, which is coupled with a proof method that computes long normal λ-terms that inhabit a formula.A rewriting-system is associated with such λ-terms, and we show that a formula admits a BB′IW-λ-term if and only if the associated rewriting-system terminates. The fact that termination is decidable is proved using a result on the finiteness of non-ascending sequences of n-tuples in Nn, which is equivalent to Kripke's Lemma

A Mechanism Linking Two Known Vulnerability Factors for Alcohol Abuse: Heightened Alcohol Stimulation and Low Striatal Dopamine D2 Receptors

Alcohol produces both stimulant and sedative effects in humans and rodents. In humans, alcohol abuse disorder is associated with a higher stimulant and lower sedative responses to alcohol. Here, we show that this association is conserved in mice and demonstrate a causal link with another liability factor: low expression of striatal dopamine D2 receptors (D2Rs). Using transgenic mouse lines, we find that the selective loss of D2Rs on striatal medium spiny neurons enhances sensitivity to ethanol stimulation and generates resilience to ethanol sedation. These mice also display higher preference and escalation of ethanol drinking, which continues despite adverse outcomes. We find that striatal D1R activation is required for ethanol stimulation and that this signaling is enhanced in mice with low striatal D2Rs. These data demonstrate a link between two vulnerability factors for alcohol abuse and offer evidence for a mechanism in which low striatal D2Rs trigger D1R hypersensitivity, ultimately leading to compulsive-like drinkingFil: Bocarsly, Miriam E.. National Institutes of Health; Estados UnidosFil: da Silva e Silva, Daniel. National Institutes of Health; Estados UnidosFil: Kolb, Vanessa. National Institutes of Health; Estados UnidosFil: Luderman, Kathryn D.. National Institutes of Health; Estados UnidosFil: Shashikiran, Sannidhi. National Institutes of Health; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Sibley, David R.. National Institutes of Health; Estados UnidosFil: Dobbs, Lauren K.. National Institutes of Health; Estados Unidos. University of Texas at Austin; Estados UnidosFil: Álvarez, Verónica Alicia. National Institutes of Health; Estados Unido

The Effect of Adverse Oil Price Shocks on Monetary Policy and Output Using a Dynamic Small Open Economy General Equilibrium Model With Staggered Price for Brazil

The aim of the present research is to use a model economy built for Brazil, based on an optimizing dynamic general equilibrium model, in order to perform numerical simulations to derive the ability of the artificial economy to explain the impact of monetary policy interventions on Brazilian short run economic performance in terms of the inflation rate, output gap, interest rate and level of economic activity in the face of an adverse oil shock. It is an extension of Bugarin et al. (2005) concentrating on the consequence of energy price increases, facing different monetary policy rules. Following Hall (1988 e 1990) and Finn (2000) it is considered that an increase in energy prices acts like a negative productivity shock. The model provides an accessible description of an artificial economy with a tractable micro-founded dynamic setting with forward looking rational agents in a small open economy with a staggered pricing mechanism that generates inflation inertia and recessionary disinflations. Alternative specification of monetary reaction functions are introduced into the model economy in order to perform a sensitivity analysis of derived impulse responses to those interventions facing the negative productivity shock. The preliminary results suggest that the introduction of habit persistence into the consumption hypothesis does not make much difference. However the introduction of different monetary reaction functions does alter the impulse response of output, inflation rate, and nominal interest rate. A common result is the decline in potential output for all models. Additionally, the only case where a reduction in the output gap is observed is when using the Taylor rule that takes into consideration the output gap and past interest rates with high persistence.

On the Influence of Latent Semantic Analysis Parameterization for Bug Localization

The bug localization problem has benefited from modern information retrieval techniques, such as Latent Semantic Analysis. There are many factors that influence the quality of results of this approach, such as, stop-words, term-documentmatrix transformations, dimensionality reduction and filtering criteria of the corpus. In this paper, we study the effect of different combinations for these factors on the impact of the accuracy of the query results in the proposed technique for bug localization. Bugs of three real-world software systems were analyzed with different combinations of input parameters for the LSA technique. Our results suggest that the term-document matrix transformations and filtering criteria of the corpus have major influence in the quality of the result and that the combination of adequate individual parameter values does not necessarily produce the best combination. Furthermore, some general guidance for parameterization of the LSA technique for bug localization could also besuggested from the observed results

Critical exponents from parallel plate geometries subject to periodic and antiperiodic boundary conditions

We introduce a renormalized 1PI vertex part scalar field theory setting in momentum space to computing the critical exponents $\nu$ and $\eta$, at least at two-loop order, for a layered parallel plate geometry separated by a distance L, with periodic as well as antiperiodic boundary conditions on the plates. We utilize massive and massless fields in order to extract the exponents in independent ultraviolet and infrared scaling analysis, respectively, which are required in a complete description of the scaling regions for finite size systems. We prove that fixed points and other critical amounts either in the ultraviolet or in the infrared regime dependent on the plates boundary condition are a general feature of normalization conditions. We introduce a new description of typical crossover regimes occurring in finite size systems. Avoiding these crossovers, the three regions of finite size scaling present for each of these boundary conditions are shown to be indistinguishable in the results of the exponents in periodic and antiperiodic conditions, which coincide with those from the (bulk) infinite system.Comment: Modified introduction and some references; new crossover regimes discussion improved; Appendixes expanded. 48 pages, no figure