213 research outputs found

    Vascular trauma: a five year review

    Get PDF
    O presente trabalho pretende avaliar a casuística dos traumatismos vasculares agudos admitidos no Serviço de Cirurgia Vascular dos Hospitais da Universidade de Coimbra (HUC) durante o período de 5 anos, compreendido entre Julho de 2004 e Junho de 2009. Foram avaliados 97 doentes, sendo a principal causa de traumatismo as lesões iatrogénicas, seguida dos acidentes de viação. No grupo de doentes não relacionados com procedimentos coronários percutâneos verificou-se que no membro superior as artérias umeral e radial foram as mais afectadas, enquanto no membro inferior foram as artérias femoral superficial e poplítea. A isquémia aguda foi a principal forma de apresentação. Relativamente ao tratamento deste grupo de doentes, a RATT (ressecção e anastomose topo-topo) e o enxerto foram os mais utlizados no membro superior, enquanto a trombectomia e o bypass foram as técnicas mais aplicadas a nível do membro inferior. Não houve mortalidade mas a morbilidade foi elevada, predominando as lesões neurológicas nos traumatismos do membro superior, e a amputação nos do membro inferior. Os resultados deste trabalho foram concordantes com o que está publicado na literatura em que se demonstra um aumento progressivo dos traumatismos de origem iatrogénica

    Vortices on Orbifolds

    Full text link
    The Abelian and non-Abelian vortices on orbifolds are investigated based on the moduli matrix approach, which is a powerful method to deal with the BPS equation. The moduli space and the vortex collision are discussed through the moduli matrix as well as the regular space. It is also shown that a quiver structure is found in the Kahler quotient, and a half of ADHM is obtained for the vortex theory on the orbifolds as the case before orbifolding.Comment: 25 pages, 4 figures; references adde

    Vortex counting from field theory

    Full text link
    The vortex partition function in 2d N = (2,2) U(N) gauge theory is derived from the field theoretical point of view by using the moduli matrix approach. The character for the tangent space at each moduli space fixed point is written in terms of the moduli matrix, and then the vortex partition function is obtained by applying the localization formula. We find that dealing with the fermionic zero modes is crucial to obtain the vortex partition function with the anti-fundamental and adjoint matters in addition to the fundamental chiral multiplets. The orbifold vortex partition function is also investigated from the field theoretical point of view.Comment: 21 pages, no figure

    Vertices, Vortices & Interacting Surface Operators

    Full text link
    We show that the vortex moduli space in non-abelian supersymmetric N=(2,2) gauge theories on the two dimensional plane with adjoint and anti-fundamental matter can be described as an holomorphic submanifold of the instanton moduli space in four dimensions. The vortex partition functions for these theories are computed via equivariant localization. We show that these coincide with the field theory limit of the topological vertex on the strip with boundary conditions corresponding to column diagrams. Moreover, we resum the field theory limit of the vertex partition functions in terms of generalized hypergeometric functions formulating their AGT dual description as interacting surface operators of simple type. Analogously we resum the topological open string amplitudes in terms of q-deformed generalized hypergeometric functions proving that they satisfy appropriate finite difference equations.Comment: 22 pages, 4 figures; v.2 refs. and comments added; v.3 further comments and typo

    Functional Inequality in Latin America: News from the Twentieth Century

    Get PDF
    We report on a novel approach for the measurement of gas adsorption in microporous solids using X-ray computed tomography (CT) that we refer to as digital adsorption. Similar to conventional macroscopic methods, the proposed protocol combines observations with an inert and an adsorbing gas to produce equilibrium isotherms in terms of the truly measurable quantity in an adsorption experiment, namely the surface excess. Most significantly, X-ray CT allows probing the adsorption process in three dimensions, so as to build spatially-resolved adsorption isotherms with a resolution of approximately 10 mm3 within a fixed-bed column. Experiments have been carried out at 25 C and in the pressure range 1-30bar using CO2 on activated carbon, zeolite 13X and glass beads (as control material), and results are validated against literature data. A scaling approach was applied to analyze the whole population of measured adsorption isotherms (~7600), leading to single universal adsorption isotherm curves that are descriptive of all voxels for a given adsorbate-adsorbent system. By analyzing the adsorption heterogeneity at multiple length scales (1 mm3 to 1 cm3), packing heterogeneity was identified as the main contributor for the larger spatial variability in the adsorbed amount observed for the activated carbon rods as compared to zeolite pellets. We also show that this technique is readily applicable to a large spectrum of commercial porous solids, and that it can be further extended to weakly adsorbing materials with appropriate protocols that reduce measurement uncertainties. As such, the obtained results prove the feasibility of digital adsorption and highlight substantial opportunities for its wider use in the field of adsorptive characterization of porous solids

    Vocal Communications and the Maintenance of Population Specific Songs in a Contact Zone

    Get PDF
    Bird song has been hypothesized to play a role in several important aspects of the biology of songbirds, including the generation of taxonomic diversity by speciation; however, the role that song plays in speciation within this group may be dependent upon the ability of populations to maintain population specific songs or calls in the face of gene flow and external cultural influences. Here, in an exploratory study, we construct a spatially explicit model of population movement to examine the consequences of secondary contact of populations singing distinct songs. We concentrate on two broad questions: 1) will population specific songs be maintained in a contact zone or will they be replaced by shared song, and 2) what spatial patterns in the distribution of songs may result from contact? We examine the effects of multiple factors including song-based mating preferences and movement probabilities, oblique versus paternal learning of song, and both cultural and genetic mutations. We find a variety of conditions under which population specific songs can be maintained, particularly when females have preferences for their population specific songs, and we document many distinct patterns of song distribution within the contact zone, including clines, banding, and mosaics
    • …
    corecore