Velocity dispersion estimates of APM galaxy clusters

We present 83 new galaxy radial velocities in the field of 18 APM clusters with redshifts between 0.06 and 0.13. The clusters have Abell identifications and the galaxies were selected within 0.75 h$^{-1}$Mpc in projection from their centers. We derive new cluster velocity dispersions for 13 clusters using our data and published radial velocities. We analyze correlations between cluster velocity dispersions and cluster richness counts as defined in Abell and APM catalogs. The correlations show a statistically significant trend although with a large scatter suggesting that richness is a poor estimator of cluster mass irrespectively of cluster selection criteria and richness definition. We find systematically lower velocity dispersions in the sample of Abell clusters that do not fulfill APM cluster selection criteria suggesting artificially higher Abell richness counts due to contamination by projection effects in this subsample.Comment: Accepted for publication in MNRA

Galaxy Peculiar Velocities and Infall onto Groups

We perform statistical analyses to study the infall of galaxies onto groups and clusters in the nearby Universe. The study is based on the UZC and SSRS2 group catalogs and peculiar velocity samples. We find a clear signature of infall of galaxies onto groups over a wide range of scales 5 h^{-1} Mpc<r<30 h^{-1} Mpc, with an infall amplitude on the order of a few hundred kilometers per second. We obtain a significant increase in the infall amplitude with group virial mass (M_{V}) and luminosity of group member galaxies (L_{g}). Groups with M_{V}<10^{13} M_{\odot} show infall velocities V_{infall} \simeq 150 km s^{-1} whereas for M_{V}>10^{13} M_{\odot} a larger infall is observed, V_{infall} \simeq 200 km s^{-1}. Similarly, we find that galaxies surrounding groups with L_{g}<10^{15} L_{\odot} have V_{infall} \simeq 100 km s^{-1}, whereas for L_{g}>10^{15} L_{\odot} groups, the amplitude of the galaxy infall can be as large as V_{infall} \simeq 250 km s^{-1}. The observational results are compared with the results obtained from mock group and galaxy samples constructed from numerical simulations, which include galaxy formation through semianalytical models. We obtain a general agreement between the results from the mock catalogs and the observations. The infall of galaxies onto groups is suitably reproduced in the simulations and, as in the observations, larger virial mass and luminosity groups exhibit the largest galaxy infall amplitudes. We derive estimates of the integrated mass overdensities associated with groups by applying linear theory to the infall velocities after correcting for the effects of distance uncertainties obtained using the mock catalogs. The resulting overdensities are consistent with a power law with \delta \sim 1 at r \sim 10 h^{-1}Mpc.Comment: 25 pages, 10 figure

Anesthesiologic effects of transperitoneal versus extraperitoneal approach during robot-assisted radical prostatectomy: results of a prospective randomized study

To compare the effects of CO(2) insufflation on hemodynamics and oxygen levels and on acid-base level during Robot-Assisted Radical Prostatectomy (RARP) with transperitoneal (TP) versus extra-peritoneal (EP) accesses

Cluster-Galaxy Correlations in CDM Models

We study the ability of COBE-normalized CDM models to reproduce observed properties of the distribution of galaxies and clusters using N-body numerical simulations. We analyze the galaxy-galaxy and cluster-galaxy two-point correlation functions, $\xi_{gg}$ and $\xi_{cg}$, in open ($\Omega_{0}=0.4, \Omega_{\Lambda}=0, \sigma_8=0.75$), and flat ($\Omega_{0}=0.3, \Omega_{\Lambda}=0.7, \sigma_8=1.05$) CDM models which both reproduce the observed abundances of rich clusters of galaxies. To compare models with observations we compute projected cross-correlation functions $\omega_{gg}$ and $\omega_{cg}$ to derive the corresponding $\xi_{gg}$ and $\xi_{cg}$. We use target galaxies selected from Las Campanas Redshift Survey, target clusters selected from the APM Cluster Survey and tracer galaxies from the Edinburgh Durham Sky Survey catalog.Comment: 13 pages, 6 figures, to appear in: The Astrophysical Journa

Seismic vulnerability maps of Timisoara historical center based on fragility curves

The seismic vulnerability assessment on a territorial scale requires the application of simplified procedures. Data collection is usually carried out by adopting external inspections; for this reason the knowledge gained for the considered buildings is usually not complete and lack of information has to be managed. The definition of a methodology which takes into account these aspects is one of the aims of this paper. Another goal is the extension of the obtained results to buildings not directly surveyed on site, whose characteristics are similar to those of the analyzed buildings. The case study of Timisoara (Romania) is presented. A rapid survey of the historical center is performed and recurring typologies are identified. Analyses of the most significant local mechanisms of collapse are implemented, taking into account possible parameters variation. Fragility curves for each typology are then obtained allowing the definition of vulnerability maps for the whole historical center

El comercio internacional de servicios en Brasil: una visión sobre la liberalización en el GATS y sus implicaciones

Texto en español y resumen en inglésLa expansión de las actividades de servicios constituye uno de los más importantes cambios acaecidos en el devenir humano en la segunda mitad del siglo XX. La evolución seguida en las últimas décadas por las economías más desarrolladas ha puesto de manifiesto que los servicios se han convertido en la forma dominante de actividad económica de los países desarrollados y en vías de desarrollo. Un multiplicado número de actividades, que responde genéricamente al nombre de servicios, tiende a concentrar la mayor parte de la ocupación y el valor de la producción en las economías desarrolladas. Así, con la entrada de Brasil en el GATS, la investigación contribuyo al mejor entendimiento y conocimiento del comercio internacional de servicios en Brasil, analizándolo en profundidad desde una perspectiva histórica y actual, tratando de identificar los principales factores sobre las implicaciones de una mayor liberalización del sector servicios negociados en el GATS. La presentación del tema elegido presento algunas respuestas a las cuestiones propuestas y principalmente profundizo el estudio de los intercambios internacionales de servicios en Brasil, en virtud de sus malos resultados en la balanza de pagos en este sector. Y principalmente diserta sobre la liberalización de los servicios en el marco del GATS enfocado en el caso de Brasil. Ensalzó sobre las implicaciones para Brasil como la importancia de la liberalización del comercio de servicios para las economías. Trazando el papel del Estado brasileño en dicha liberalización y las barreras impuestas al comercio de servicios que pueden ser llevados a cabo por los Estados. Sin embargo, el foco principal de la tesis fue desarrolla sobre la liberalización de los servicios en el marco del GATS, aludiendo algunas implicaciones que pueden ser buenas y malas para Brasil si no fueren hechas las negociaciones con políticas adecuadas para el país

Extinction Effects in Spiral Galaxy Rotation Curves

Observations show that the slope of the inner part of the H$\alpha$/[NII] rotation curves of disk galaxies is depressed by extinction: at fixed luminosity, the observed slope is in fact seen to depend on the disk inclination to the line of sight. Using a simple extinction model, we are able to reproduce well the observed trends. The model assumes an exponential distribution, both in the radial and $z$ directions, identical for star--forming regions and dust. Fits to the data are optimized by varying the scale height and scale length of absorbers, as well as the disk's central optical depth $\tau_\circ$, as seen face--on. The observations indicate that disk central opacity increases with total luminosity. Model fits for the most luminous galaxies (brighter than $M-5\log h=-21.4$ in the I band) yield $\tau_\circ \simeq 3.5^{+4.0}_{-2.0}$, near $\lambda=0.66$ $\mu$m. The large uncertainty on the inferred value of $\tau_\circ$ is due to the poorly known characteristics of the distribution of absorbers in the disk, as well as to the likelihood of strong departures from an exponential radial distribution near the galaxy centers.Comment: 19 pages, 5 figures, accepted for publication in A

Deprojection of luminosity functions of galaxies in the Coma cluster

We use a simple analytic model to deproject 2-d luminosity functions (LF) of galaxies in the Coma cluster measured by Beijersbergen et al. 2002. We demonstrate that the shapes of the LFs change after deprojection. It is therefore essential to correct LFs for projection effects. The deprojected LFs of the central area have best-fitting Schechter parameters of M^{*}_U=-18.31^{+0.08}_{-0.08} and \alpha_U=-1.27^{+0.018}_{-0.018}, M^{*}_B=-19.79^{+0.14}_{-0.15} and \alpha_B=-1.44^{+0.016}_{-0.016} and M^{*}_r=-21.77^{+0.20}_{-0.28} and \alpha_r=-1.27^{+0.012}_{-0.012}. The corrections are not significant enough to change the previously observed trend of increasing faint end slopes with increasing distance to the cluster center. The weighted U, B, and r band slopes of the deprojected LFs show a slightly weaker steepening with increasing projected cluster radius.Comment: Accepted for publication in A&A as a Research Not