Quantum chaotic resonances from short periodic orbits

We present an approach to calculating the quantum resonances and resonance wave functions of chaotic scattering systems, based on the construction of states localized on classical periodic orbits and adapted to the dynamics. Typically only a few of such states are necessary for constructing a resonance. Using only short orbits (with periods up to the Ehrenfest time), we obtain approximations to the longest living states, avoiding computation of the background of short living states. This makes our approach considerably more efficient than previous ones. The number of long lived states produced within our formulation is in agreement with the fractal Weyl law conjectured recently in this setting. We confirm the accuracy of the approximations using the open quantum baker map as an example.Comment: 4 pages, 4 figure

Semiclassical approach to universality in quantum chaotic transport

The statistics of quantum transport through chaotic cavities with two leads is encoded in transport moments $M_m={\rm Tr}[(t^\dag t)^m]$, where $t$ is the transmission matrix, which have a known universal expression for systems without time-reversal symmetry. We present a semiclassical derivation of this universality, based on action correlations that exist between sets of long scattering trajectories. Our semiclassical formula for $M_m$ holds for all values of $m$ and arbitrary number of open channels. This is achieved by mapping the problem into two independent combinatorial problems, one involving pairs of set partitions and the other involving factorizations in the symmetric group.Comment: Published version. Changes in presentatio

Contenção farmacológica de jacares com Triiodoetilato de Galamina.

Para atender aos trabalhos que exigem a manipulação de jacares, como obtenção de dados biometricos, coleta de amostra de conteudo estomacal,procurou-se verificar o efeito do triiodoetilato de galamina(flaxedil) como agente contensor, para a espécie caima crocodilus yacare

Quartic Anomalous Couplings in γγ\gamma\gamma Colliders

We study the constraints on the vertices $W^+W^- Z\gamma$, $W^+W^-\gamma\gamma$, and $ZZ\gamma\gamma$ that can be obtained from triple-gauge-boson production at the next generation of linear $e^+e^-$ colliders operating in the $\gamma\gamma$ mode. We analyze the processes $\gamma\gamma \to W^+W^-V$ ($V=Z$, or $\gamma$) and show that these reactions increase the potential of $e^+e^-$ machines to search for anomalous four-gauge-boson interactions.Comment: 15 pages, Latex file using ReVteX, 4 uufiled figures include

Biological and molecular characterization of an isolate of Tobacco streak virus obtained from soybeans in Brazil.

A virus was isolated from soybean (Glycine max) plants with symptoms of dwarfing and bud blight in Wenceslau Braz County, Paraná, Brazil. The host range and properties resembled those of Tobacco streak virus (TSV). The purified virus showed three peaks in a frozen sucrose gradient. Antiserum was produced and the virus was serologically related to TSV. Electron microscopy detected 28 nm spherical particles. Coat protein (CP) had a Mr of 29.880 Da. A fragment of 1028 nt was amplified, cloned and sequenced. One open reading frame with 717 nt was identified and associated to the CP. The CP gene shared 83% identity with the sequence of TSV CP from white clover (Trifolium repens) (GenBank CAA25133). This is the first report of the biological and molecular characterization of TSV isolated from soybeans. It is proposed that this isolate be considered a strain of TSV named TSV-BR

Identifying the Higgs Boson in Electron--Photon Collisions

We analyze the production and detection of the Higgs boson in the next generation of linear $e^+e^-$ colliders operating in the $e\gamma$ mode. In particular, we study the production mechanism $e + \gamma \rightarrow e \gamma \gamma \rightarrow e + H$, where one photon is generated via the laser backscattering mechanism, while the other is radiated via the usual bremsstrahlung process. We show that this is the most important mechanism for Higgs boson production in a $500$ GeV $e\gamma$ collider for M_H\raisebox{-.4ex}{\rlap{\sim}} \raisebox{.4ex}{>}140 GeV. We also study the signals and backgrounds for detection of the Higgs in the different decay channels, $b \bar b$, $W^+W^-$, and $ZZ$, and suggest kinematical cuts to improve the signature of an intermediate mass Higgs boson.Comment: (REVTEX 2.0, 12 pages and 9 figures available upon request, Preprint MAD/PH/753

Non-Hermitian Hamiltonians of Lie algebraic type

We analyse a class of non-Hermitian Hamiltonians, which can be expressed bilinearly in terms of generators of a sl(2,R)-Lie algebra or their isomorphic su(1,1)-counterparts. The Hamlitonians are prototypes for solvable models of Lie algebraic type. Demanding a real spectrum and the existence of a well defined metric, we systematically investigate the constraints these requirements impose on the coupling constants of the model and the parameters in the metric operator. We compute isospectral Hermitian counterparts for some of the original non-Hermitian Hamiltonian. Alternatively we employ a generalized Bogoliubov transformation, which allows to compute explicitly real energy eigenvalue spectra for these type of Hamiltonians, together with their eigenstates. We compare the two approaches.Comment: 27 page

Relação de Meloidogyne arenaria com o desenvolvimento radicular do porta-enxerto SO4. de videira

O objetivo deste trabalho foi avaliar a relação entre a presença de Meloidogyne arenaria no solo e o desenvolvimento radicular do porta-enxerto SO4 de videira. Foram avaliados, além deste porta-enxerto, o ?Harmony? e o ?IAC 766? por serem amplamente utilizados na vitivinicultura do Submédio do Vale do São Francisco. O enraizamento foi feito em solo autoclavado contido em sacos para formação de mudas. Após 40 dias, as mudas foram transplantadas para vasos com capacidade de 20 L, conforme os seguintes tratamentos: 1) solo natural -- infestado com M. arenaria -- 2) solo autoclavado e com inoculação das mudas e 3) solo autoclavado e sem inoculação das mudas com M. arenaria. Após 6 meses, nenhuma anormalidade foi observada, visualmente, no sistema radicular dos porta-enxertos avaliados. Observou-se que o nematoide não se multiplicou de forma diferenciada nos três porta-enxertos, mas que o porta-enxerto ?Harmony? pode vir a se tornar uma opção de substituição do ?SO4? por se apresentar com tendências a maior vigor do sistema radicular, visto não ter ocorrido diferença significativa no número de ovos quantificados nos três porta-enxertos

Estudos Citogenéticos em fêmeas infectadas ou não pelo vírus da leucose enzoótica bovina (VLB).

A leucose enzoótica bovina, causada por um oncovírus (vírus tipo C bovino) se caracteriza pelo desenvolvimento de neoplasias, podendo envolver desde nódulos linfáticos isolados até órgãos internos e a pele

Rendimento de biomassa da palma Miúda irrigada sob doses de adubação orgânica e intensidades de corte.

Resumo: No semiárido nordestino existe um severo déficit na oferta de forragem e a palma forrageira apresenta-se como uma alternativa para melhorar o desempenho dos rebanhos. No entanto, em vários municípios do Rio Grande do Norte ocorrem murchas severas da palma. Assim, a utilização da irrigação com quantidade mínima de água tem sido uma opção para sua produção nessas regiões. A pesquisa objetivou avaliar o efeito da adubação orgânica e de diferentes intensidades de corte sobre a produção de matéria verde (PMV) e seca (PMS) da palma forrageira cv. Miúda (Nopalea cochenillifera) sob condições de irrigação com 12 meses de rebrota. Foi utilizado o delineamento inteiramente casualizado em parcelas subdivididas, onde as doses da adubação orgânica (20, 40 e 60 Mg ha-1 ano-1) constituíram às parcelas e as intensidades de corte (deixando somente o cladódio mãe, todos os primários e todos os secundários) as subparcelas, com seis repetições. O plantio foi feito no espaçamento 2,0 x 0,10 m (50.000 plantas ha-1). A água utilizada na irrigação foi classificada como C4S1T3. A lâmina aplicada foi de cinco litros (2,5 mm) por metro a cada sete dias ou 10 mm por mês. O sistema de irrigação foi o de gotejamento em fileiras simples. As intensidades de corte e adubação orgânica influenciaram a PMV e a PMS. A maior PMS (30,47 Mg ha-1ano-1) foi obtida quando todos os cladódios secundários foram preservados e com aplicação de 37,5 Mg ha-1ano-1de esterco bovino. [Biomass yield of irrigated Miúda spineless forage cactus under organic fertilization doses and different cutting intensities]. Abstract: In the Brazilian Northeast semi-arid region there is a severe deficit in the supply of fodder and forage and cactus pear is an important alternative to improve the performance of the herds. However, in several municipalities of Rio Grande do Norte State occur severe withered of these cacti. Thus, the use of irrigation with a minimum amount of water has been an option for production in these regions. The research aimed to evaluate the effect of organic fertilizer (bovine manure) and different cutting intensities on the production of fresh (PFM) and dry matter (PDM)) of spineless cactus pear cv. Miúda (Nopalea cochenillifera) under irrigation with 12 months of regrowth. A completely randomized design with a split plot was applied, where organic fertilizers doses (20, 40 and 60 Mg ha-1 yr-1) were the main plots and cutting intensities (leaving only the mother cladode, all primary and all secondary cladodes), the subplots, with six replicates. The planting was done in 2.0 x 0.10 m spacing (50,000 plants ha-1). The water used for irrigation was classified as C4S1T3. The lamina applied was 2.5 mm every seven days or 10 mm month-1. The irrigation system was dripping in single rows. The cutting intensities and organic fertilization influenced the PFM and PDM. The highest PDM (30.47 Mg ha-1 yr-1) was obtained when all secondary cladodes were preserved with an application of 37.5 Mg ha-1 yr-1 of bovine manure