Quantum-classical transition and quantum activation of ratchet currents in the parameter space

The quantum ratchet current is studied in the parameter space of the dissipative kicked rotor model coupled to a zero temperature quantum environment. We show that vacuum fluctuations blur the generic isoperiodic stable structures found in the classical case. Such structures tend to survive when a measure of statistical dependence between the quantum and classical currents are displayed in the parameter space. In addition, we show that quantum fluctuations can be used to overcome transport barriers in the phase space. Related quantum ratchet current activation regions are spotted in the parameter space. Results are discussed {based on quantum, semiclassical and classical calculations. While the semiclassical dynamics involves vacuum fluctuations, the classical map is driven by thermal noise.Comment: 6 pages, 3 figure

Ensino de física em um centro de Ciências : novas vivências da força gravitacional

A pesquisa analisa aspectos do Ensino de Física em Centros de Ciências. A pesquisa é realizada na “Casa Maluca” do Centro de Divulgação Científica e Cultural da Universidade de São Paulo. Esta é uma casa com piso inclinado com ângulos de 15º em relação ao referencial externo, o que provoca alterações na percepção de alguns fenômenos relacionado à força da gravidade. O objetivo é entender como este espaço fisicamente alterado influencia as noções e explicações acerca da gravidade pelos estudantes do Ensino Médio. Tomamos como referencial teórico às noções de obstáculos epistemológicos proposta por Gaston Bachelard e metodologia de pesquisa quantitativa e qualitativa. Os resultados mostram as dificuldades dos alunos em entender o conceito gravidade e seu caráter vetorial e apontam à presença de alguns obstáculos epistemológicos

Microcavity polariton-like dispersion doublet in resonant Bragg gratings

Periodic structures resonantly coupled to excitonic media allow the existence of extra intragap modes ('Braggoritons'), due to the coupling between Bragg photon modes and 3D bulk excitons. This induces unique and unexplored dispersive features, which can be tailored by properly designing the photonic bandgap around the exciton resonance. We report that one-dimensional Braggoritons realized with semiconductor gratings have the ability to mimic the dispersion of quantum-well microcavity polaritons. This will allow the observation of new nonlinear phenomena, such as slow-light-enhanced nonlinear propagation and an efficient parametric scattering at two 'magic frequencies'

Diagnóstico preliminar da agricultura familiar na Transamazônica: indicações para pesquisa e desenvolvimento.

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Localised prostate cancer and hemophilia A (AHA): Case report and management of the disease.

Acquired Hemophilia A (AHA) is a rare bleeding diathesis characterized by the development of autoantibodies against factor VIII (FVIII). About half of the cases are idiopathic and the other half are associated with autoimmune diseases, postpartum problems, infections, inflammatory bowel disease, drugs, lymphoproliferative disorders or solid tumors . AHA is associated with malignancies in 7-15% of cases. We report a case of AHA in a 65 year old patient with prostatic carcinoma, who underwent retropubic radical prostatectomy (RP)

Simposio : la historia de la ciencia en la enseñanza de las ciencias

A pesar de la casi total unanimidad acerca de la importancia de la historia y de la filosofía de la ciencia para conseguir el objetivo de una educación científica de calidad para todos y todas, hay diversas problemáticas que obturan la presencia efectiva de estas metaciencias en las aulas de ciencias de los distintos niveles educativos. En este simposio se reúnen trabajos con carácter teórico y práctico sobre la inserción de la historia y la filosofía de la ciencia en la enseñanza de las ciencias, con especial énfasis en la formación inicial y continuada del profesorado de ciencias

2D Image head pose estimation via latent space regression under occlusion settings

Head orientation is a challenging Computer Vision problem that has been extensively researched having a wide variety of applications. However, current state-of-the-art systems still underperform in the presence of occlusions and are unreliable for many task applications in such scenarios. This work proposes a novel deep learning approach for the problem of head pose estimation under occlusions. The strategy is based on latent space regression as a fundamental key to better structure the problem for occluded scenarios. Our model surpasses several state-of-the-art methodologies for occluded HPE, and achieves similar accuracy for non-occluded scenarios. We demonstrate the usefulness of the proposed approach with: (i) two synthetically occluded versions of the BIWI and AFLW2000 datasets, (ii) real-life occlusions of the Pandora dataset, and (iii) a real-life application to human-robot interaction scenarios where face occlusions often occur. Specifically, the autonomous feeding from a robotic arm