In vitro clonal behavior of Olea europaea L., variety Galega vulgar

A multiplicação clonal da cultivar de oliveira Galega vulgar por estacaria semi-lenhosa, é impedida pelas baixas taxas de enraizamento, as quais, segundo alguns autores, não ultrapassam os 10%, originando assim desequilíbrios entre a procura e a oferta bem como preços de mercado mais elevados face a outras cultivares de fácil enraizamento. A micropropagação por rebentação axilar surge como uma técnica alternativa de clonagem, por originar rejuvenescimento das plantas e taxas de enraizamento in vitro próximas ou iguais a 100%. Utilizando estacas de árvores adultas do pomar clonal de Galega vulgar existente na ESAS, anterior e parcialmente caracterizado por outras Instituições para a) presença de vírus; b) taxas de enraizamento; c) rendimento em azeite, introduziram-se aleatoriamente 39 clones in vitro, existindo actualmente 15 clones in vitro. Sendo raras as publicações sobre estudos de diferenças clonais no comportamento in vitro na oliveira e noutras espécies, este trabalho apresenta os resultados obtidos nos estudos efectuados desde 2003 para 15 clones, respeitantes à 1) introdução de material vegetal; 2) controlo de bacterioses sistémicas; 3) caracterização da variação interclonal nas taxas de multiplicação, enraizamento e aclimatação.Clonal multiplication of olive variety Galega vulgar trough leafy steam cuttings is impeded by low rooting rates, according to some authors do not overcome 10% of success. Those situations originates imbalances between plant offer and market demand as well as higher prices of plants face others varieties. Micropropagation trough adventitious multiplication is a technical proceeding able for cloning recalcitrant woody plants. Trough rejuvenation of plants, rates of 100% in rooting is achieved. Using cuttings from adult trees of a clonal orchard of Galega vulgar in ESAS, previously and partially characterized for a) presence of virus; b) rooting rates of cuttings; c) olive oil yield, 39 clones where randomly introduced in vitro for an actual collection of 15 in vitro clones. Published papers concerning in vitro clonal behavior for olive or other species are rare, thus, this work presents the obtained results since 2003 for 1) introduction of clones; 2) systemic bacterioses control; 3) clonal variation in multiplication, rooting and acclimatizatio

Three little pieces for computer and relativity

Numerical relativity has made big strides over the last decade. A number of problems that have plagued the field for years have now been mostly solved. This progress has transformed numerical relativity into a powerful tool to explore fundamental problems in physics and astrophysics, and I present here three representative examples. These "three little pieces" reflect a personal choice and describe work that I am particularly familiar with. However, many more examples could be made.Comment: 42 pages, 11 figures. Plenary talk at "Relativity and Gravitation: 100 Years after Einstein in Prague", June 25 - 29, 2012, Prague, Czech Republic. To appear in the Proceedings (Edition Open Access). Collects results appeared in journal articles [72,73, 122-124

Mass-Energy and Momentum Extraction by Gravitational Wave Emission in the Merger of Two Colliding Black Holes: The Non-Head-On Case

We examine numerically the post-merger regime of two Schwarzschild black holes in non head-on collision. Our treatment is made in the realm of non-axisymmetric Robinson-Trautman spacetimes which are appropriate for the description of the system. Characteristic initial data for the system are constructed and the Robinson-Trautman equation is integrated using a numerical code based on the Galerkin spectral method. The collision is planar, restricted to the plane determined by the directions of the two initial colliding black holes, with the net momentum fluxes of gravitational waves confined to this plane. We evaluate the efficiency of mass-energy extraction, the total energy and momentum carried out by gravitational waves and the momentum distribution of the remnant black hole. Our analysis is based on the Bondi-Sachs four momentum conservation laws. Head-on collisions and orthogonal collisions constitute, respectively, upper and lower bounds to the power emission and to the efficiency of mass-energy extraction by gravitational waves. The momentum extraction and the pattern of the momentum fluxes, as a function of the incidence angle, are examined. The momentum extraction characterizes a regime of strong deceleration of the system. The angular pattern of gravitational wave signals is also examined. They are typically bremsstrahlung for early times emission. Gravitational waves are also emitted outside the plane of collision but this component has a zero net momentum flux. The relation between the incidence angle of collision and the exit angle of the remnant closely approximates a relation for inelastic collisions of classical particles in Newtonian dynamics.Comment: 18 pages, 12 Figures, published with slight modifications in Phys. Rev. D 85, 024003 (2012

Cultivares de milho para o nordeste brasileiro: ensaios realizados no ano de 1997.

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Recomendações de cultivares de milho para os ecossistemas dos tabuleiros costeiros, agreste e sertão.

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