2,081 research outputs found

    Identificação e clonagem de promotores raiz-específicos de eucalipto.

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    A utilização de promotores tecido - específicos é uma das principais estratégias para direcionar a expres são de transgenes a determinados órgãos ou tipos celulares . Por isso, o objetivo deste trabalho foi a clonagem de promotores raiz - específicos , a partir de dados de RNA - Seq obtidos de bibliotecas de raiz, xilema e folha de eucalipto. Dois genes com padrão d e expressão preferencial em raiz foram inicialmente selecionados para isolamento da região promotora. Fragmentos de 1kb foram clonados em vetor binário pCAMBIA2301, fusionados ao gene repórter da beta - glucuronidase (GUS) , para transformação de Populus trem ula x Populus alba via Agrobacterium tumefaciens .Edição dos anais do 3º Simpósio de Bioquímica e Biotecnologia, 2013. Londrina

    Efficient coupling of photons to a single molecule and the observation of its resonance fluorescence

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    Single dye molecules at cryogenic temperatures display many spectroscopic phenomena known from free atoms and are thus promising candidates for fundamental quantum optical studies. However, the existing techniques for the detection of single molecules have either sacrificed the information on the coherence of the excited state or have been inefficient. Here we show that these problems can be addressed by focusing the excitation light near to the absorption cross section of a molecule. Our detection scheme allows us to explore resonance fluorescence over 9 orders of magnitude of excitation intensity and to separate its coherent and incoherent parts. In the strong excitation regime, we demonstrate the first observation of the Mollow triplet from a single solid-state emitter. Under weak excitation we report the detection of a single molecule with an incident power as faint as 150 attoWatt, paving the way for studying nonlinear effects with only a few photons.Comment: 6 figure

    Coherent State Preparation and Observation of Rabi Oscillations in a Single Molecule

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    We report on the excitation of single molecules via narrow zero-phonon transitions using short laser pulses. By monitoring the Stokes-shifted fluorescence, we studied the excited state population as a function of the delay time, laser intensity, and frequency detuning. A pi-pulse excitation was demonstrated with merely 500 photons, and 5 Rabi cycles were achieved at higher excitation powers. Our findings are in good agreement with theoretical calculations and provide a first step toward coherent manipulation of the electronic states of single molecules with few photons.Comment: 4 pages, 3 figure

    `In pursuit of the Nazi mind?' the deployment of psychoanalysis in the allied struggle against Germany

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    This paper discusses how psychoanalytic ideas were brought to bear in the Allied struggle against the Third Reich and explores some of the claims that were made about this endeavour. It shows how a variety of studies of Fascist psychopathology, centred on the concept of superego, were mobilized in military intelligence, post-war planning and policy recommendations for ‘denazification’. Freud's ideas were sometimes championed by particular army doctors and government planners; at other times they were combined with, or displaced by, competing, psychiatric and psychological forms of treatment and diverse studies of the Fascist ‘personality’. This is illustrated through a discussion of the treatment and interpretation of the deputy leader of the Nazi Party, Rudolf Hess, after his arrival in Britain in 1941

    Brane Formation and Cosmological Constraint on the Number of Extra Dimensions

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    Special relativity is generalized to extra dimensions and quantized energy levels of particles are obtained. By calculating the probability of particles' motion in extra dimensions at high temperature of the early universe, it is proposed that the branes may have not existed since the very beginning of the universe, but formed later. Meanwhile, before the formation, particles of the universe may have filled in the whole bulk, not just on the branes. This scenario differs from that in the standard big bang cosmology in which all particles are assumed to be in the 4D spacetime. So, in brane models, whether our universe began from a 4D big bang singularity is questionable. A cosmological constraint on the number of extra dimensions is also given which favors N7N\geq 7.Comment: 11 pages, no figures. To appear in IJT

    Phase diagram of S=1/2 XXZ chain with NNN interaction

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    We study the ground state properties of one-dimensional XXZ model with next-nearest neighbor coupling alpha and anisotropy Delta. We find the direct transition between the ferromagnetic phase and the spontaneously dimerized phase. This is surprising, because the ferromagnetic phase is classical, whereas the dimer phase is a purely quantum and nonmagnetic phase. We also discuss the effect of bond alternation which arises in realistic systems due to lattice distortion. Our results mean that the direct transition between the ferromagnetic and spin-Peierls phase occur.Comment: 4 pages, 2 eps figure

    The prescribed mean curvature equation in weakly regular domains

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    We show that the characterization of existence and uniqueness up to vertical translations of solutions to the prescribed mean curvature equation, originally proved by Giusti in the smooth case, holds true for domains satisfying very mild regularity assumptions. Our results apply in particular to the non-parametric solutions of the capillary problem for perfectly wetting fluids in zero gravity. Among the essential tools used in the proofs, we mention a \textit{generalized Gauss-Green theorem} based on the construction of the weak normal trace of a vector field with bounded divergence, in the spirit of classical results due to Anzellotti, and a \textit{weak Young's law} for (Λ,r0)(\Lambda,r_{0})-minimizers of the perimeter.Comment: 23 pages, 1 figure --- The results on the weak normal trace of vector fields have been now extended and moved in a self-contained paper available at: arXiv:1708.0139
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