Thermal treatment of superconductor thin film of the BSCCO system using domestic microwave oven

In this work, we report the preparation of a superconductor thin film of the BSCCO system using a good quality powder with nominal composition Bi_{1.8}Pb_{0.4}Sr_2CaCu_2O_x which was thermally treated using a domestic microwave oven (2.45 GHz, 800 W). This film was grew on a single crystal of LaAlO_3(100) substrate and exhibited a crystalline structure with the c-axis perpendicular to the plane of the substrate. An onset superconducting transition temperature was measured at 80 K.Comment: 4 pages, 5 figure

The Two-Component Virial Theorem and the Physical Properties of Stellar Systems

Motivated by present indirect evidences that galaxies are surrounded by dark matter halos, we investigate whether their physical properties can be described by a formulation of the virial theorem which explicitly takes into account the gravitational potential term representing the interaction of the dark halo with the barionic or luminous component. Our analysis shows that the application of such a ``two-component virial theorem'' not only accounts for the scaling relations displayed, in particular, by elliptical galaxies, but also for the observed properties of all virialized stellar systems, ranging from globular clusters to galaxy clusters.Comment: 13 pages, 2 figures, LaTeX, corrected few typos. This version matches the published versio

Polarimetry of Compact Symmetric Objects

We present multi-frequency VLBA observations of two polarized Compact Symmetric Objects (CSOs), J0000+4054 and J1826+1831, and a polarized CSO candidate, J1915+6548. Using the wavelength-squared dependence of Faraday rotation, we obtained rotation measures (RMs) of -180 \pm 10 rad m^-2 and 1540 \pm 7 rad m^-2 for the latter two sources. These are lower than what is expected of CSOs (several 1000 rad m^-2) and, depending on the path length of the Faraday screens, require magnetic fields from 0.03 to 6 \mu G. These CSOs may be more heavily affected by Doppler boosting than their unpolarized counterparts, suggesting that a jet-axis orientation more inclined towards the line of sight is necessary to detect any polarization. This allows for low RMs if the polarized components are oriented away from the depolarizing circumnuclear torus. These observations also add a fourth epoch to the proper motion studies of J0000+4054 and J1826+1831, constraining their kinematic age estimates to >610 yrs and 2600 \pm 490 yrs, respectively. The morphology, spectrum, and component motions of J1915+6548 are discussed in light of its new classification as a CSO candidate, and its angle to the line of sight (~50\deg) is determined from relativistic beaming arguments.Comment: 29 pages, including 9 figures; Accepted by Astrophysical Journal, 16 Feb 0

Modulation of gene expression in ex vitro grapevine (Vitis vinifera L.) by hormonal, oxidant and anti-oxidant stimuli

When in vitro plantlets developed under low light conditions are exposed to high light upon transfer to ex vitro, it is common to observe symptoms of oxidative stress. In order to unravel more of what takes place in this phase of transition, paramount for plant survival, the present study focused on the expression of genes coding for proteins related with the metabolic pathways most affected upon transfer to ex vitro and monitored their expression in response to hormones and chemicals inducing alternative sinks for photosynthetic electron transport (PET) and reactive oxygen species (ROS) production. The expression of eight genes was significantly downregulated after all the treatments: catalase, beta-glucosidase, cytochrome P450, vegetative storage protein 2, wak1, a calcium binding protein, a meprin and TRAF homology domain-containing protein and a serine/threonine kinase. It was possible to verify that abscisic acid (ABA) was able to revert light induced gene expression and that the PET inhibitors DCMU and DPI had the same effect as ABA. ABA and jasmonic acid showed parallel effects, as both induced the expression of the same set of genes. Finally, exogenous cytokinin, instead of enhancing the plant´s response to high light led to the downregulation of light-responsive genes

Axial Multicentric Osteosarcoma in an English Cocker Spaniel

No abstract available

Transição agroecológica: construção participativa do conhecimento para a sustentabilidade: projeto macroprograma 1: resultados de atividades 2009-2010.

A trajetória da Agroecologia na Embrapa possui dois momentos marcantes, que contribuíram para a consolidação do tema na agenda da instituição. O lançamento do Marco Referencial em Agroecologia em 2006, que contribuiu para a institucionalização da Agroecologia na Embrapa, e a aprovação do projeto "Transição Agroecológica: Construção participativa do conhecimento para a sustentabilidade", em 2008, que concretizou essa institucionalização. Esta história, ainda que parcial, está contada no Relatório de Atividades do Projeto Transição Agroecológica no período 2009-2010. Muitos dos resultados aqui apresentados ainda carecem de complementação, a ser buscada com a continuidade dos trabalhos a serem desenvolvidos nos dois anos subsequentes do projeto. No entanto, não se teve qualquer dúvida quanto à validade de se lançar este relatório, mesmo que parcial, narrando os avanços já obtidos. É um registro pioneiro, que serve para análise e reflexão da própria equipe do projeto e que traz para a comunidade técnico-científica dados que, sem dúvida, contribuem para abreviar o caminho a ser percorrido durante a jornada da transição agroecológica.bitstream/item/65201/1/15775.pd