Spin-1/2 geometric phase driven by decohering quantum fields

We calculate the geometric phase of a spin-1/2 system driven by a one and two mode quantum field subject to decoherence. Using the quantum jump approach, we show that the corrections to the phase in the no-jump trajectory are different when considering an adiabatic and non-adiabatic evolution. We discuss the implications of our results from both the fundamental as well as quantum computational perspective.Comment: 4 page

Coherent evolution via reservoir driven holonomy

We show that in the limit of strongly interacting environment a system initially prepared in a Decoherence Free Subspace (DFS) coherently evolves in time, adiabatically following the changes of the DFS. If the reservoir cyclicly evolves in time, the DFS states acquire an holonomy.Comment: 4 page

Otimização de protocolo para o enraizamento in vitro de jalapa (Mandevilla illustris) (Vell.) R. E. Woodson.

Suplemento. Edição dos Trabalhos do 49 Congresso Brasileiro de Olericultura, Águas de Lindóia, ago. 2009

Ocorrência de fungos micorrízicos em catuaba (Anemopaegma arvense (Vell.) Stell. ex de Souza - Bignoniaceae), uma planta medicinal do Cerrado em risco de extinção.

Este trabalho foi realizado com o objetivo de verificar a ocorrência de fungos micorrízicos, identificar suas espécies, e avaliar a colonização em raízes de plantas de diferentes populações e variedades de Anemopaegma arvense, uma planta medicinal do Cerrado em risco de extinção. As avaliações da colonização micorrízica e identificação de espécies de fungos micorrízicos arbusculares (FMAs) foram realizadas no Laboratório de Microbiologia do Solo da Universidade Federal de Lavras (UFLA). Foram utilizadas raízes de 10 plantas coletadas em diferentes locais juntamente com as amostras de solo próximo ao sistema radicular de populações naturais das variedades: glabra, puberula e petiolata. Os esporos foram extraídos do solo por meio da metodologia de peneiramento úmido e, para a avaliação e observação da colonização radicular, as raízes coradas foram observadas em microscópio estereoscópico (ampliação 10 a 40x). Em todas as amostras analisadas foi possível identificar espécies de FMAs, exceto para a variedade puberula, coletada no município de Mogi Guaçu-SP. O número de esporos variou de maneira significativa entre as amostras e os locais amostrados, não havendo distribuição regular. Acaulospora scrubiculata, A. spinosa, A. longula, Escustelospora heterogama, Paraglomus occultum, Gigaspora margarita, Gigaspora sp., dentre outros, encontram-se entre as espécies identificadas. Quanto à avaliação da colonização micorrízica nas raízes, observou-se que todas as variedades foram colonizadas no sitema radicular, verificada por meio da presença de hifas. No entanto, a colonização não foi constatada em todas as amostras avaliadas e também não foi observada a formação de arbúsculos e/ou vesículas.Suplemento 1

Diversidade genética em populações naturais de infalível.

Suplemento. Edição dos Trabalhos do 49 Congresso Brasileiro de Olericultura, Águas de Lindóia, ago. 2009

Dressing approach to the nonvanishing boundary value problem for the AKNS hierarchy

We propose an approach to the nonvanishing boundary value problem for integrable hierarchies based on the dressing method. Then we apply the method to the AKNS hierarchy. The solutions are found by introducing appropriate vertex operators that takes into account the boundary conditions.Comment: Published version Proc. Quantum Theory and Symmetries 7 (QTS7)(Prague, Czech Republic, 2011

The Need for Knowledge Extraction: Understanding Harmful Gambling Behavior with Neural Networks

Responsible gambling is a field of study that involves supporting gamblers so as to reduce the harm that their gambling activity might cause. Recently in the literature, machine learning algorithms have been introduced as a way to predict potentially harmful gambling based on patterns of gambling behavior, such as trends in amounts wagered and the time spent gambling. In this paper, neural network models are analyzed to help predict the outcome of a partial proxy for harmful gambling behavior: when a gambler “self-excludes”, requesting a gambling operator to prevent them from accessing gambling opportunities. Drawing on survey and interview insights from industry and public officials as to the importance of interpretability, a variant of the knowledge extraction algorithm TREPAN is proposed which can produce compact, human-readable logic rules efficiently, given a neural network trained on gambling data. To the best of our knowledge, this paper reports the first industrial-strength application of knowledge extraction from neural networks, which otherwise are black-boxes unable to provide the explanatory insights which are crucially required in this area of application. We show that through knowledge extraction one can explore and validate the kinds of behavioral and demographic profiles that best predict self-exclusion, while developing a machine learning approach with greater potential for adoption by industry and treatment providers. Experimental results reported in this paper indicate that the rules extracted can achieve high fidelity to the trained neural network while maintaining competitive accuracy and providing useful insight to domain experts in responsible gambling

Geometric phase in open systems

We calculate the geometric phase associated to the evolution of a system subjected to decoherence through a quantum-jump approach. The method is general and can be applied to many different physical systems. As examples, two main source of decoherence are considered: dephasing and spontaneous decay. We show that the geometric phase is completely insensitive to the former, i.e. it is independent of the number of jumps determined by the dephasing operator.Comment: 4 pages, 2 figures, RevTe

Rinoscopia e coleta de amostra utilizando a associação de um endoscópio rígido com uma pinça de biópsia longa flexível em cão

O artigo não apresenta resumo

Evidence for eikonal zeros in the momentum transfer space

We present the results of fitting elastic $pp$ differential cross section data at 23.5 $\leq \sqrt{s} \leq$ 62.5 GeV with a novel analytic parametrization for the scattering amplitude. Making use of a fitting method, the errors from the free parameters are propagated to the imaginary part of the eikonal in the momentum transfer space. A novel systematic study of the effects coming from data at large momentum transfer is also performed. We find statistical evidence for the existence of eikonal zeros in the interval of momentum transfer 5-9 $GeV^{2}$.Comment: Text with 9 pages in Revtex (preprint form), 8 figures in PostScript. Replaced with small changes. Final version to be published in Physical Review