The brightest group galaxies and their large-scale environment

We use a sample of galaxy groups in SDSS data to study their brightestgalaxies (BGG), separating groups according to their large scale environment. The statistical properties of the BGG depend on the surrounding environment on large scales, characterized by the high density peaks within Future Virialized Structures (FVS). We also find that the luminosity, colour, stellar masses and concentration index of the BGG hosted by groups in superstructures are different, with statistical significance, from the corresponding properties of BGG hosted by groups elsewhere. Moreover, this signal is strongly dominated by disk-type galaxies.The results reveal connections between the large scale environment and the accretion process onto the brightest group galaxies.Estudiamos las galaxias más luminosas (del inglés Brightest Group Galaxy, BGG) de una muestra de grupos de galaxias en el SDSS, discriminando submuestras de grupos según su estructura circundante en gran escala. Encontramos que las propiedades de las BGG dependen del ambiente en gran escala, caracterizado por su pertenencia a los picos de densidad dentro de estructuras virializadas en el futuro (del inglés Future Virialized Structures, FVS). Los valores de luminosidad, índice de color, masa estelar e índice de concentración de las BGG alojadas en grupos en FVS difieren con significancia estadística de aquellas que no se encuentran en superestructuras. Esta señal está dominada por galaxias tipo disco. Estos resultados revelan conexiones entre la estructura en gran escala y los procesos de aglomeración de masa en grupos de galaxias.http://adsabs.harvard.edu/abs/2015BAAA...57...67LpublishedVersionFil: Luparello, Heliana E. Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Lares Harbin Latorre, Marcelo. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Luparello, Heliana E. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Lares Harbin Latorre, Marcelo. Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Paz, Dante Javier. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Paz, Dante Javier. Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Yaryura, Claudia Yamila. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Yaryura, Claudia Yamila. Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Fil: Lambas, Diego García. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; Argentina.Fil: Lambas, Diego García. Conicet. Instituto de Astronomía Teórica y Experimental; Argentina.Astronomía (incluye Astrofísica y Ciencias del Espacio

In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

Aqueous extracts from Posidonia oceanica’s green and brown (beached) leaves and rhizomes were prepared, submitted to phenolic compound and proteomic analysis, and examined for their potential cytotoxic effect on HepG2 liver cancer cells in culture. The chosen endpoints related to survival and death were cell viability and locomotory behavior, cell-cycle analysis, apoptosis and autophagy, mitochondrial membrane polarization, and cell redox state. Here, we show that 24 h exposure to both green-leaf- and rhizome-derived extracts decreased tumor cell number in a dose– response manner, with a mean half maximal inhibitory concentration (IC50) estimated at 83 and 11.5 µg of dry extract/mL, respectively. Exposure to the IC50 of the extracts appeared to inhibit cell motility and long-term cell replicating capacity, with a more pronounced effect exerted by the rhizomederived preparation. The underlying death-promoting mechanisms identified involved the downregulation of autophagy, the onset of apoptosis, the decrease in the generation of reactive oxygen species, and the dissipation of mitochondrial transmembrane potential, although, at the molecular level, the two extracts appeared to elicit partially differentiating effects, conceivably due to their diverse composition. In conclusion, P. oceanica extracts merit further investigation to develop novel promising prevention and/or treatment agents, as well as beneficial supplements for the formulation of functional foods and food-packaging material with antioxidant and anticancer propertie

Measurement of pion, kaon and proton production in proton-proton collisions at s=7\sqrt{s}=7 TeV

The measurement of primary $\pi^{\pm}$, K$^{\pm}$, p and $\overline{p}$ production at mid-rapidity ($|y| <$ 0.5) in proton-proton collisions at $\sqrt{s} = 7$ TeV performed with ALICE (A Large Ion Collider Experiment) at the Large Hadron Collider (LHC) is reported. Particle identification is performed using the specific ionization energy loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/$c$ for pions, from 0.2 up to 6 GeV/$c$ for kaons and from 0.3 up to 6 GeV/$c$ for protons. The measured spectra and particle ratios are compared with QCD-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.Comment: 33 pages, 19 captioned figures, 3 tables, authors from page 28, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/156

Effects of superstructure environment on galaxy groups

We analyse properties of galaxy groups and their dependence on the large-scale environment as defined by superstructures. We find that group–galaxy cross–correlations depend only on group properties regardless the groups reside in superstructures. This indicates that the total galaxy density profile around groups is independent of the global environment. At a given global luminosity, a proxy to group total mass, groups have a larger stellar mass content by a factor 1.3, a relative excess independent of the group luminosity. Groups in superstructures have 40 per cent higher velocity dispersions and systematically larger minimal enclosing radii. We also find that the stellar population of galaxies in groups in superstructures is systematically older as infered from the galaxy spectra Dn 4000 parameter. Although the galaxy number density profile of groups is independent of environment, the star–formation rate and stellar mass profile of the groups residing in superstructures differs from groups elsewhere. For groups residing in superstructures, the combination of a larger stellar mass content and star–formation rate produces a larger time–scale for star formation regardless the distance to the group center. Our results provide evidence that groups in superstructures formed earlier than elsewhere, as expected in the assembly bias scenario.publishedVersio

The influence of superstructures on bright galaxy environments: clustering properties

We analyse the dependence of clustering properties of galaxies as a function of their large-scale environment. In order to characterize the environment on large scales, we use the catalogue of future virialized superstructures (FVS) by Luparello et al. and separate samples of luminous galaxies according to whether or not they belong to FVS. In order to avoid biases in the selection of galaxies, we have constructed different subsamples so that the distributions of luminosities and masses are comparable outside and within FVS. As expected, at large scales, there is a strong difference between the clustering of galaxies inside and outside FVS. However, this behaviour changes at scales r < 1 Mpc/h, where the correlations have similar amplitudes. The amplitude of the two-halo term of the correlation function for objects inside FVS does not depend on their mass, but rather on that of the FVS. This is confirmed by comparing this amplitude with that expected from extended Press-Schechter fits. In order to compare these observational results with current models for structure formation, we have performed a similar analysis using a semi-analytic implementation in a LCDM cosmological model. We find that the cross-correlation functions from the mock catalogue depend on the large-scale structures in a similar way to the observations. From our analysis, we conclude that the clustering of galaxies within the typical virialized regions of groups, mainly depends on the halo mass, irrespective of the large-scale environment.Comment: 12 pages, 9 figures, modified to match accepted version in MNRA

INFN What Next: Ultra-relativistic Heavy-Ion Collisions

This document was prepared by the community that is active in Italy, within INFN (Istituto Nazionale di Fisica Nucleare), in the field of ultra-relativistic heavy-ion collisions. The experimental study of the phase diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP) deconfined state will proceed, in the next 10-15 years, along two directions: the high-energy regime at RHIC and at the LHC, and the low-energy regime at FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the present and future programme of the ALICE experiment, the upgrade of which will open, in the 2020s, a new phase of high-precision characterisation of the QGP properties at the LHC. As a complement of this main activity, there is a growing interest in a possible future experiment at the SPS, which would target the search for the onset of deconfinement using dimuon measurements. On a longer timescale, the community looks with interest at the ongoing studies and discussions on a possible fixed-target programme using the LHC ion beams and on the Future Circular Collider.Comment: 99 pages, 56 figure

Розвиток ідеї європейської інтеграції та її значення для України

У статті аналізується сутність ідеї європейської інтеграції, її еволюція протягом століть. Досліджуються теоретичні основи формування та розвитку Європейського Союзу, обґрунтовується необхідність євроінтеграційної стратегії України як ключового пріоритету зовнішньої та внутрішньої політики нашої держави.The article analyses the essence of the idea of European integration, its evolution during the centuries and researches the theoretical foundations of the formation and development of the European Union, proves the need for European integration strategy of Ukraine as a key priority of foreign and internal policy