Extended reagions of radio emission not associated with the AGN phenomenon as sources of acceleration of cosmic rays: The case of cD galaxies

Diffuse, non-thermal extended emission not associated with the AGN phenomenon, found in many clusters of galaxies hosted by an AGN, are related to the acceleration of cosmic rays. In the current work we present preliminary evidence of absence of such formations in clusters of galaxies hosted by optically identified cD galaxies. Our subsample consists of three powerful low redshift radiogalaxies, centered in poor clusters of galaxies. We have searched for radio relics and (mini)halos which could be forming as a result of the confinement of cosmic rays by bubbles creayed by the AGN. We report on the work in progress.Comment: 4 pages, Conference HEPRO II

An Incremental Learning Method to Support the Annotation of Workflows with Data-to-Data Relations

Workflow formalisations are often focused on the representation of a process with the primary objective to support execution. However, there are scenarios where what needs to be represented is the effect of the process on the data artefacts involved, for example when reasoning over the corresponding data policies. This can be achieved by annotating the workflow with the semantic relations that occur between these data artefacts. However, manually producing such annotations is difficult and time consuming. In this paper we introduce a method based on recommendations to support users in this task. Our approach is centred on an incremental rule association mining technique that allows to compensate the cold start problem due to the lack of a training set of annotated workflows. We discuss the implementation of a tool relying on this approach and how its application on an existing repository of workflows effectively enable the generation of such annotations

Analysis of the main passive soft tissues associated with adult acquired flatfoot deformity development: A computational modeling approach

Adult acquired flatfoot deformity (AAFD) is a pathology with a wide range of treatment options. Physicians decide the best treatment based on their experience, so the process is entirely subjective. A better understanding of soft tissue stress and its contribution in supporting the plantar arch could help to guide the clinical decision. Traditional experimental trials cannot consistently evaluate the contribution of each tissue. Therefore, in this research a 3-Dimensional FE foot model was reconstructed from a normal patient in order to measure the stress of the passive stabilizers of the arch, and its variation in different scenarios related with intermediate stages of AAFD development. All bones, the plantar fascia (PF), cartilages, plantar ligaments and the spring ligament (SL) were included, respecting their anatomical distribution and biomechanical characteristics. An AAFD evaluation scenario was simulated. The relative contribution of each tissue was obtained comparing each result with a normal case. The results show that PF is the main tissue that prevents the arch elongation, while SL mainly reduces the foot pronation. Long and short plantar ligaments play a secondary role in this process. The stress increment on both PF and SL when one of two fails suggests that these tissues complement each other. These findings support the theory that regards the tibialis posterior tendon as a secondary actor in the arch maintenance, compared with the PF and the SL, because this tendon is overstretched by the hindfoot pronation around the talonavicular joint. This approach could help to improve the understanding of AAFD

Differential protein expression analysis to study the pathogenicity of the protozoa parasite Trichomonas Gallinae

Comunicaciones a congreso

The Origin of the Brightest Cluster Galaxies

Most clusters and groups of galaxies contain a giant elliptical galaxy in their centres which far outshines and outweighs normal ellipticals. The origin of these brightest cluster galaxies is intimately related to the collapse and formation of the cluster. Using an N-body simulation of a cluster of galaxies in a hierarchical cosmological model, we show that galaxy merging naturally produces a massive, central galaxy with surface brightness and velocity dispersion profiles similar to observed BCG's. To enhance the resolution of the simulation, 100 dark halos at $z=2$ are replaced with self-consistent disk+bulge+halo galaxy models following a Tully-Fisher relation using 100000 particles for the 20 largest galaxies and 10000 particles for the remaining ones. This technique allows us to analyze the stellar and dark matter components independently. The central galaxy forms through the merger of several massive galaxies along a filament early in the cluster's history. Galactic cannibalism of smaller galaxies through dynamical friction over a Hubble time only accounts for a small fraction of the accreted mass. The galaxy is a flattened, triaxial object whose long axis aligns with the primordial filament and the long axis of the cluster galaxy distribution agreeing with observed trends for galaxy-cluster alignment.Comment: Revised and accepted in ApJ, 25 pages, 10 figures, online version available at http://www.cita.utoronto.ca/~dubinski/bcg

Mechanical Behavior of Natural Hydraulic Lime Mortars

Natural hydraulic lime (NHL) mortars are widely used for restoration works due to their good compatibility with the substrate material in terms of physical, chemical, and mechanical properties. Regarding their mechanical characterization, there is still a need for further understanding of their fracture behavior and the influence of their dosage methodology on the mechanical properties. Thus, this chapter focuses on the mechanical characterization of NHL mortars, such as flexural, compressive, and splitting tensile strengths, elastic modulus, and fracture energy. Moreover, the influence of the composition and production process on such properties was studied as well. Furthermore, the loading rate effect on the fracture behavior was also presented. The results show that NHL mortars have shape and size effect on the compressive strength. In addition, NHL mortar is rate sensitive, mainly due to the viscous effects caused by the presence of free water in the porous structure

The Dependence of Galaxy Shape on Luminosity and Surface Brightness Profile

For a sample of 96,951 galaxies from the Sloan Digital Sky Survey Data Release 3, we study the distribution of apparent axis ratios as a function of r-band absolute magnitude and surface brightness profile type. We use the parameter fracDeV to quantify the profile type (fracDeV = 1 for a de Vaucouleurs profile; fracDeV = 0 for an exponential profile). When the apparent axis ratio q_{am} is estimated from the moments of the light distribution, the roundest galaxies are very bright (M_r \sim -23) de Vaucouleurs galaxies and the flattest are modestly bright (M_r \sim -18) exponential galaxies. When the apparent axis ratio q_{25} is estimated from the axis ratio of the 25 mag/arcsec^2 isophote, we find that de Vaucouleurs galaxies are flatter than exponential galaxies of the same absolute magnitude. For a given surface brightness profile type, very bright galaxies are rounder, on average, than fainter galaxies. We deconvolve the distributions of apparent axis ratios to find the distribution of the intrinsic short-to-long axis ratio gamma, assuming constant triaxiality T. For all profile types and luminosities, the distribution of apparent axis ratios is inconsistent with a population of oblate spheroids, but is usually consistent with a population of prolate spheroids. Bright galaxies with a de Vaucouleurs profile (M_r < -21.84, fracDeV > 0.9) have a distribution of q_{am} that is consistent with triaxiality in the range 0.4 < T < 0.8, with mean intrinsic axis ratio 0.66 < gamma < 0.69. The fainter de Vaucouleurs galaxies are best fit with prolate spheroids (T = 1) with mean axis ratio gamma = 0.51.Comment: 32 pages, 12 figures, to appear in Ap

Globular Clusters in Dense Clusters of Galaxies

Deep imaging data from the Keck II telescope are employed to study the globular cluster (GC) populations in the cores of six rich Abell clusters. The sample includes A754, A1644, A2124, A2147, A2151, and A2152, and spans the redshift range z = 0.035-0.066. The clusters also range in morphology from spiral-rich, irregular systems to centrally concentrated cD clusters rich in early-type galaxies. Globular cluster specific frequencies S_N and luminosity function dispersions are measured for a total of 9 galaxies in six central fields. The measured values of S_N for the six brightest cluster galaxies (BCGs) are all higher than typical values for giant ellipticals, in accord with the known S_N-density correlations. The three non-BCGs analyzed also have elevated values of S_N, confirming that central location is a primary factor. The number of GCs per unit mass for these fields are consistent with those found in an earlier sample, giving further evidence that GC number scales with mass and that the S_N variations are due to a deficit of halo light, i.e., S_N reflects mass-to-light ratio. The discussion builds on an earlier suggestion that the GCs (both metal rich and metal poor) around the central cluster galaxies were assembled at early times, and that star formation halted prematurely in the central galaxies at the epoch of cluster collapse. This is consistent with recent simulations of BCG/cluster formation. The subsequent addition of luminous material through cluster dynamical evolution can cause S_N to decrease, and we may be seeing the first evidence of this. Finally, the GC luminosity function measurements are used to constrain the relative distances of the three clusters that make up the Hercules supercluster.Comment: Uses emulateapj.sty (included); 17 pages with 9 included PostScript figures. Figures 1-6 are separate GIF images (so 15 figures total) available from http://astro.caltech.edu/~jpb/clusters -- the full PostScript version of the paper (20 pages; 2.2 Mb compressed) incorporating Figures 1-6 can also be grabbed from this URL. Accepted for publication in A

N-body simulations of galaxies and groups of galaxies with the Marseille GRAPE systems

I review the Marseille GRAPE systems and the N-body simulations done with them. I first describe briefly the available hardware and software, their possibilities and their limitations. I then describe work done on interacting galaxies and groups of galaxies. This includes simulations of the formation of ring galaxies, simulations of bar destruction by massive compact satellites, of merging in compact groups and of the formation of brightest members in clusters of galaxies.Comment: 13 pages, 5 figures, to be published in "Non-linear Dynamics and Chaos in Astrophysics", eds. J.R. Buchler, S. Gottesman, J. Hunter and H. Kandrup, Annals of the New York Academy of Science