659 research outputs found

    Nonlinear Schrodinger equation with chaotic, random, and nonperiodic nonlinearity

    Full text link
    In this paper we deal with a nonlinear Schr\"{o}dinger equation with chaotic, random, and nonperiodic cubic nonlinearity. Our goal is to study the soliton evolution, with the strength of the nonlinearity perturbed in the space and time coordinates and to check its robustness under these conditions. Comparing with a real system, the perturbation can be related to, e.g., impurities in crystalline structures, or coupling to a thermal reservoir which, on the average, enhances the nonlinearity. We also discuss the relevance of such random perturbations to the dynamics of Bose-Einstein Condensates and their collective excitations and transport.Comment: 4 pages, 6 figure

    Avaliação sensorial de uvas de mesa produzidas na região do Vale do São Francisco.

    Get PDF
    Com o objetivo de apoiar as pesquisas da Embrapa, que visam a seleção e adaptação de novas cultivares de videira para consumo in natura no Submédio do Vale do São Francisco, este trabalho avaliou a aceitação junto híbridos potenciais e de variedades de uvas com semente que não são comumente comercializadas na região

    Oral Complications of HIV Disease

    Get PDF
    Oral lesions are among the early signs of HIV infection and can predict its progression to acquired immunodeficiency syndrome (AIDS). A better understanding of the oral manifestations of AIDS in both adults and children has implications for all health care professionals. The knowledge of such alterations would allow for early recognition of HIV-infected patients. The present paper reviews epidemiology, relevant aspects of HIV infection related to the mouth in both adults and children, as well as current trends in antiretroviral therapy and its connection with orofacial manifestations related to AIDS

    Distinct fos-expressing neuronal ensembles in the ventromedial prefrontal cortex mediate food reward and extinction memories

    Get PDF
    In operant learning, initial reward-associated memories are thought to be distinct from subsequent extinction-associated memories. Memories formed during operant learning are thought to be stored in “neuronal ensembles.” Thus, we hypothesize that different neuronal ensembles encode reward- and extinction-associated memories. Here, we examined prefrontal cortex neuronal ensembles involved in the recall of reward and extinction memories of food self-administration.Wefirst trained rats to lever press for palatable food pellets for 7 d (1 h/d) and then exposed them to 0, 2, or 7 daily extinction sessions in which lever presses were not reinforced. Twenty-four hours after the last training or extinction session, we exposed the rats to either a short 15 min extinction test session or left them in their homecage (a control condition). We found maximal Fos (a neuronal activity marker) immunoreactivity in the ventral medial prefrontal cortex of rats that previously received 2 extinction sessions, suggesting that neuronal ensembles in this area encode extinction memories. We then used the Daun02 inactivation procedure to selectively disrupt ventral medial prefrontal cortex neuronal ensembles that were activated during the 15 min extinction session following 0 (no extinction) or 2 prior extinction sessions to determine the effects of inactivating the putative food reward and extinction ensembles, respectively, on subsequent nonreinforced food seeking 2 d later. Inactivation of the food reward ensembles decreased food seeking, whereas inactivation of the extinction ensembles increased food seeking. Our results indicate that distinct neuronal ensembles encoding operant reward and extinction memories intermingle within the same cortical area

    Efeitos da desfolha e desponte de ramos sobre a composição físico química de Syrah elaborados em dois ciclos de produção no Vale do São Francisco.

    Get PDF
    O objetivo deste estudo foi avaliar a influência de diferentes tratamentos de despontes de ramos e desfolha sobre a composição físico-química do vinho da variedade Syrah produzidos no Submédio do Vale do São Francisco com uvas colhidas em diferentes épocas do ano

    Trocas gasosas em videira Syrah sobre dois sistemas de condução.

    Get PDF
    O objetivo deste trabalho foi avaliar as trocas gasosas em videira Syrah (Vitis vinifera L.) cultivada em dois sistemas de condução no Submédio do São Francisco

    Caracterização do índice de pigmentos em videira Syrah cultivada em dois sistemas de condução no Submédio São Francisco, PE.

    Get PDF
    O objetivo deste trabalho foi avaliar e o índice relativo de clorofila em plantas de videira cultivadas em dois sistemas de conduçã
    corecore