Observing the build-up of the colour-magnitude relation at redshift ~0.8

We analyse the rest-frame (U-V) colour-magnitude relation for 2 clusters at redshift 0.7 and 0.8, drawn from the ESO Distant Cluster Survey. By comparing with the population of red galaxies in the Coma cluster, we show that the high redshift clusters exhibit a deficit of passive faint red galaxies. Our results show that the red-sequence population cannot be explained in terms of a monolithic and synchronous formation scenario. A large fraction of faint passive galaxies in clusters today has moved onto the red sequence relatively recently as a consequence of the fact that their star formation activity has come to an end at z<0.8.Comment: 5 pages, 2 figures, to appear in Proc. of IAU Colloq. 195: "Outskirts of Galaxy Clusters: Intense Life in the Suburbs" -- minor typos correcte

How much do needlestick injuries cost? a systematic review of the economic evaluations of needlestick and sharps injuries among healthcare personnel

objective. To provide an overview of the economic aspects of needlestick and sharps injury (NSI) management among healthcare personnel (HCP) within a Health Technology Assessment project to evaluate the impact of safety-engineered devices on health care methods. A systematic review of economic analyses related to NSIs was performed in accordance with the PRISMA statement and by searching PubMed and Scopus databases (January 1997–February 2015). Mean costs were stratified by study approach (modeling or data driven) and type of cost (direct or indirect). Costs were evaluated using the CDC operative definition and converted to 2015 International US dollars (Int$). results. A total of 14 studies were retrieved: 8 data-driven studies and 6 modeling studies. Among them, 11 studies provided direct and indirect costs and 3 studies provided only direct costs. The median of the means for aggregate (direct + indirect) costs was Int$747 (range, Int$199–Int$1,691). The medians of the means for disaggregated costs were Int$425 (range, Int$48–Int$1,516) for direct costs (9 studies) and Int$322 (range, Int$152–Int$413) for indirect costs (6 studies). When compared with data-driven studies, modeling studies had higher disaggregated and aggregated costs, but data-driven studies showed greater variability. Indirect costs were consistent between studies, mostly referring to lost productivity, while direct costs varied widely within and between studies according to source infectivity, HCP susceptibility, and post-exposure diagnostic and prophylactic protocols. Costs of treating infections were not included, and intangible costs could equal those associated with NSI medical evaluations. conclusions. NSIs generate significant direct, indirect, potential, and intangible costs, possibly increasing over time. Economic efforts directed at preventing occupational exposures and infections, including provision of safety-engineered devices, may be offset by the savings from a lower incidence of NSIs

Lo scambio della conoscenza attraverso il canale della ricerca a contratto: un’analisi dei “conto terzi” delle Università di Trieste e Udine

3nonenoneBenedetti G.; De Stefano D.; Salera A.Benedetti, MARIA GABRIELLA; DE STEFANO, Domenico; Salera, Antoni

The evolution of galaxy sizes

We present a study of galaxy sizes in the local Universe as a function of galaxy environment, comparing clusters and the general field. Galaxies with radii and masses comparable to high-z massive and compact galaxies represent 4.4% of all galaxies more massive than 3 X 10^{10} M_sun in the field. Such galaxies are 3 times more frequent in clusters than in the field. Most of them are early-type galaxies with intermediate to old stellar populations. There is a trend of smaller radii for older luminosity-weighted ages at fixed galaxy mass. We show the relation between size and luminosity-weighted age for galaxies of different stellar masses and in different environments. We compare with high-z data to quantify the evolution of galaxy sizes. We find that, once the progenitor bias due to the relation between galaxy size and stellar age is removed, the average amount of size evolution of individual galaxies between high- and low-z is mild, of the order of a factor 1.6.Comment: to appear in the proceedings of the IAU S295: The intriguing life of massive galaxies, editors D. Thomas, A. Pasquali & I. Ferrera

Sull’avvio del canone negli studi di storia dell’arte contemporanea nell’era della globalizzazione digitale. Spunti da uno scritto di Cesare Segre

Il saggio propone un ragionamento sull’interazione, sempre più diffusa nella pratica artistica attuale, tra l’autore e il fruitore nella realizzazione dell’opera d’arte. Interazione, coinvolgimento da parte di un pubblico più o meno consapevole, che, certamente, può ritenersi per le arti visive ormai una pratica acquisita ma che, tuttavia, può aprire, se non nuove prospettive, nuovi interrogativi. Secondo l’autrice, infatti, lo storico dell’arte, intervenendo sulla contemporaneità, non può ignorare, nell’epoca dell’intermedialità, nei tempi dell’abbattimento delle frontiere tra i vari generi artistici, nella realtà di una comunità culturale che deve confrontarsi, inevitabilmente, con il web e particolarmente con il web 2.0, espressione delle reti sociali, quella che Segre ha definito come «paternità frazionata» dell’opera d’arte. Ha senso parlare ancora, quindi, alla luce di questi cambiamenti, di fronte a questa nuova tipologia di proposte e in un’età definita ormai come interattiva, di autore e di opera? E, infine, proprio sulla scia di questi cambiamenti, le parole e le modalità d’intervento della critica militante devono darsi un nuovo statuto?The essay offers a reasoning on interaction between the author and the audience in the artwork’s creation, more and more common in current artistic practice. Interaction by a public more or less conscious, which can be now considered an assimilated practice for the visual arts but which, however, may open, if not new perspectives, new questions. According to the author, in fact, the art historian who intervenes on contemporaneity cannot ignore what Segre has defined as artwork’s «paternità frazionata», considering that we are in the intermediality era, in the times of abolishing borders between the various artistic genres, in a cultural community that must inevitably confront, with the web, and particularly with the web 2.0 social networks’ expression. Then does it still makes sense, in light of these changes, in front of this new kind of proposals and in an age now defined as interactive, to talk about of author and artwork? And finally, just in the wake of these changes, does militant criticism’ words and action modalities must give themselves a new statute

The evolution of the colour-magnitude relation and of the star formation activity in galaxy clusters since z~0.8

We present recent results on the evolution of the colour-magnitude relation and of the star formation activity in galaxy clusters since z~0.8. Results are based on the ESO Distant Cluster Survey (EDisCS) - an ESO large programme aimed at the study of cluster structure and cluster galaxy evolution over a significant fraction of cosmic time - and are discussed in the framework of the current standard paradigm of structure formation.Comment: 8 pages, 5 figure, to appear in ASP Conference Series (Proceedings of the 1st Subaru International Conference "Panoramic Views of Galaxy Formation and Evolution", held in Japan, 10-15 December 2007

Quenching of Star Formation

In the last decade we have seen an enormous increase in the size and quality of spectroscopic galaxy surveys, both at low and high redshift. New statistical techniques to analyse large portions of galaxy spectra are now finding favour over traditional index based methods. Here we will review a new robust and iterative Principal Component Analysis (PCA) algorithm, which solves several common issues with classic PCA. Application to the 4000AA break region of galaxies in the VIMOS VLT Deep Survey (VVDS) and Sloan Digital Sky Survey (SDSS) gives new high signal-to-noise ratio spectral indices easily interpretable in terms of recent star formation history. In particular, we identify a sample of post-starburst galaxies at z~0.7 and z~0.07. We quantify for the first time the importance of post-starburst galaxies, consistent with being descendants of gas-rich major mergers, for building the red sequence. Finally, we present a comparison with new low and high redshift "mock spectroscopic surveys" derived from a Millennium Run semi-analytic model.Comment: 7 pages, 3 figures. Conference proceedings in "Classification and Discovery in Large Astronomical Surveys", 2008, C.A.L. Bailer-Jones (ed.

Matching the dark matter profiles of dSph galaxies with those of simulated satellites: a two parameter comparison

We compare the dark matter halos' structural parameters derived for four Milky Way dwarf spheroidal galaxies to those of subhalos found in cosmological $N$-body simulations. We confirm that estimates of the mass at a single fixed radius are fully consistent with the observations. However, when a second structural parameter such as the logarithmic slope of the dark halo density profile measured close to the half-light radius is included in the comparison, we find little to no overlap between the satellites and the subhalos. Typically the right mass subhalos have steeper profiles at these radii than measurements of the dSph suggest. Using energy arguments we explore if it is possible to solve this discrepancy by invoking baryonic effects. Assuming that feedback from supernovae can lead to a reshaping of the halos, we compute the required efficiency and find entirely plausible values for a significant fraction of the subhalos and even as low as 0.1%. This implies that care must be taken not to exaggerate the effect of supernovae feedback as this could make the halos too shallow. These results could be used to calibrate and possibly constrain feedback recipes in hydrodynamical simulations.Comment: 6 pages, 3 figures, submitted to ApJ