1,397 research outputs found

    Simulation of noise-assisted transport via optical cavity networks

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    Recently, the presence of noise has been found to play a key role in assisting the transport of energy and information in complex quantum networks and even in biomolecular systems. Here we propose an experimentally realizable optical network scheme for the demonstration of the basic mechanisms underlying noise-assisted transport. The proposed system consists of a network of coupled quantum optical cavities, injected with a single photon, whose transmission efficiency can be measured. Introducing dephasing in the photon path this system exhibits a characteristic enhancement of the transport efficiency that can be observed with presently available technology.Comment: 8 pages, 7 figures. New version with more detail

    Difficulty and obstacles with the concept of variable

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    Confocal microscopy study of the distribution, content and activity of mitochondria during Paracentrotus lividus development

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    In the present paper we applied confocal microscopy and fluorescence technologies for studying the distribution and the oxidative activity of sea urchin (Paracentrotus lividus) mitochondria during development, by in vivo incubating eggs and embryos with cell-permeant MitoTracker probes. We calculated, by a mathematical model, the intensity values, the variations of intensity, and the variation index of incorporated fluorochromes. Data demonstrate that mitochondrial mass does not change during development, whereas mitochondrial respiration increases. In addition, starting from 16 blastomeres stage, some regions of the embryo contain organelles more active in oxygen consumption

    Quantum walks of two correlated photons in a 2D synthetic lattice

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    Quantum walks represent paradigmatic quantum evolutions, enabling powerful applications in the context of topological physics and quantum computation. They have been implemented in diverse photonic architectures, but the realization of two-particle dynamics on a multidimensional lattice has hitherto been limited to continuous-time evolutions. To fully exploit the computational capabilities of quantum interference it is crucial to develop platforms handling multiple photons that propagate across multidimensional lattices. Here, we report a discrete-time quantum walk of two correlated photons in a two-dimensional lattice, synthetically engineered by manipulating a set of optical modes carrying quantized amounts of transverse momentum. Mode-couplings are introduced via the polarization-controlled diffractive action of thin geometric-phase optical elements. The entire platform is compact, efficient, scalable, and represents a versatile tool to simulate quantum evolutions on complex lattices. We expect that it will have a strong impact on diverse fields such as quantum state engineering, topological quantum photonics, and Boson Sampling

    Quantum walks of two correlated photons in a 2D synthetic lattice

    Get PDF
    Quantum walks represent paradigmatic quantum evolutions, enabling powerful applications in the context of topological physics and quantum computation. They have been implemented in diverse photonic architectures, but the realization of a two-particle dynamics on a multi-dimensional lattice has hitherto been limited to continuous-time evolutions. To fully exploit the computational capabilities of quantum interference it is crucial to develop platforms handling multiple photons that propagate across multi-dimensional lattices. Here, we report a discrete-time quantum walk of two correlated photons in a two-dimensional lattice, synthetically engineered by manipulating a set of optical modes carrying quantized amounts of transverse momentum. Mode-couplings are introduced via the polarization-controlled diffractive action of thin geometric-phase optical elements. The entire platform is compact, efficient, scalable, and represents a versatile tool to simulate quantum evolutions on complex lattices. We expect that it will have a strong impact on diverse fields such as quantum state engineering, topological quantum photonics, and Boson Sampling.Comment: 18 pages, 11 figure

    The correlation between score-based protocol for equine joint assessment and subsequent arthroscopic intervention outcomes

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    This study aimed to grade joint abnormalities in horses submitted to therapeutic arthroscopy using score-based protocols for equine joint assessment, correlated with arthroscopic treatment outcomes and owner satisfaction. In this prospective study, we evaluated 126 joints of athletic horses referred for arthroscopy. The joints were scored according to findings of medical history and physical, radiographic, ultrasonographic and arthroscopic examination. Lameness, positive response to flexion test and decreased maximum joint flexion angle were detected in more than 50% of joints. Soft tissue swelling, sclerosis, subchondral bone osteolysis and single osteochondral fragments were the most common radiographic findings. Ultrasonographic examination revealed changes in synovial fluid volume and appearance, and subchondral bone irregularities. Increased vascularity of the synovial villi, chondral fibrillation, chondral fissures and superficial cartilage erosions were the most significant arthroscopic findings. The approaches that demonstrated greater sensitivity and correlation with treatment outcome and owner satisfaction were medical history, ultrasonographic and arthroscopic examination. The scoring protocol employed to grade joint abnormalities enabled the creation of a joint score system for the objective assessment, thus determining the most frequent findings and establishing an injury severity score for each joint.O objetivo desse estudo foi avaliar as anormalidades articulares observadas em equinos submetidos à artroscopia terapêutica, utilizando protocolos baseados em pontuações e correlacionando os resultados do tratamento cirúrgico com a satisfação do proprietário. Neste estudo prospectivo, foram avaliadas 126 articulações de cavalos atletas, encaminhados para artroscopia. As articulações foram pontuadas de acordo com os achados da anamnese e exame físico, exame radiográfico, exame ultrassonográfico e avaliação artroscópica. A claudicação, resposta positiva ao teste de flexão e diminuição do ângulo máximo de flexão articular foram detectados em mais de 50% das articulações. Aumento de volume dos tecidos moles, esclerose subcondral, osteólise subcondral e fragmentos osteocondrais únicos foram os achados radiográficos mais comuns. O exame ultrassonográfico revelou, com frequência, as alterações no volume e na aparência do líquido sinovial, além de irregularidades osteocondrais. O aumento da vascularização das vilosidades sinoviais, fibrilação condral, fissuras condrais e erosões superficiais da cartilagem foram os achados artroscópicos mais significativos. As abordagens diagnósticas que demonstraram maior sensibilidade e melhor correlação entre o resultado do tratamento e satisfação do proprietário foram história médica, exame ultrassonográfico e artroscópico. O protocolo de avaliação utilizado, baseado em um sistema de pontuação das anormalidades articulares observadas em cada exame, permitiu uma avaliação objetiva, ressaltando os achados mais frequentes e estabelecendo um escore de gravidade da lesão para cada articulação
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