3,754 research outputs found
Molecular gas and star formation in M81
We present IRAM 30m observations of the central 1.6 kpc of the spiral M81
galaxy. The molecular gas appears weak and with an unusual excitation physics.
We discuss a possible link between low CO emission and weak FUV surface
brightness.Comment: 2 pages, 2 figures, to appear in "Pathways through an eclectic
Universe", J. H. Knapen, T. J. Mahoney, and A. Vazdekis (Eds.), ASP Conf.
Ser., 200
Are truncated stellar disks linked to the molecular gas density?
We know that the slope of the radial, stellar light distribution in galaxies
is well described by an exponential decline and this distribution is often
truncated at a break radius (). We don't have a clear understanding for
the origin of these outer truncations and several hypotheses have been proposed
to explain them. We want to test the various theories with direct observations
of the cold molecular gas for a few truncated galaxies in comparison with the
non-truncated ones. The answer to the existence of a possible link between
truncated stellar disks and the molecular gas density cannot be obtained from
CO maps in the literature, because so far there are no galaxies with a clear
truncation observed in CO at high resolution.Comment: 3 pages, 6 figures, to appear in Astrophysics and Space Science
(Apss), special issue of "Science with ALMA: a new era for Astrophysics"
conference, ed. Dr. Bachille
Galaxy evolution in nearby groups. II. Galaxy evolution in nearby loose groups. II. Photometric and kinematic characterization of USGC U268 and USGC U376 group members in the Leo cloud
We present the photometric and kinematic characterization of two groups, USGC
U268 and USGC U376 located in different regions of the Leo cloud. U268,
composed of 10 catalogued members and 11 new added members, has a small
fraction (~24%) of early-type galaxies (ETGs). U376 has 16 plus 8 new added
members, with ~38% of ETGs. We find the presence of significant substructures
in both groups suggesting that they are likely accreting galaxies. U268 is
located in a more loose environment than U376. For each member galaxy, broad
band integrated and surface photometry have been obtained in far-UV and near-UV
with GALEX, and in u,g, r, i, z (SDSS) bands. H_alpha imaging and 2D high
resolution kinematical data have been obtained using PUMA Scanning Fabry-Perot
interferometer at the 2.12 m telescope in San Pedro M\'artir, (Baja California,
M\'exico). We improved the galaxy classification and we detected morphological
and kinematical distortions that may be connected to either on-going and/or
past interaction/accretion events or environmental induced secular evolution.
U268 appears more active than U376, with a large fraction of galaxies showing
interaction signatures (60% vs. 13%). The presence of bars among late-type
galaxies is ~10% in U268 and ~$29% in U376. The cumulative distribution of (FUV
- NUV) colours of galaxies in U268 is significantly different than that in U376
with galaxies in U268 bluer than those in U376. In the (FUV-r vs. M_r) and
(NUV-r vs. M_r) planes no members of U268 are found in the `red sequence', even
early-type galaxies lie in the `blue sequence' or in the `green valley'. Most
(80%) of the early-type members in U376 inhabits the `red sequence, a large
fraction of galaxies, of different morphological types, are located in the
`green valley', while the `blue sequence' is under-populated with respect to
U268.Comment: 27 pages, 11 figures, 8 tables, accepted for publication in MNRAS
(abridged abstract
The Orthogonal Gaseous Kinematical Decoupling in the Sa Spiral NGC 2855
We present major and minor-axis kinematics of stars and ionized gas as well
as narrow and broad-band surface photometry of the Sa spiral NGC 2855. In the
nuclear regions of this unbarred and apparently undisturbed spiral galaxy the
gas is rotating perpendicularly to the galaxy disk. We suggest that this
kinematically-decoupled component is the signature of an acquisition process in
the history of this galaxy.Comment: 7 pages, 4 PostScript figures. Accepted for pubblication in A&A.
Figs. 1 and 3 at lower resolution. Data tables will be available at CD
Anti-oxidant potential and gap junction-mediated intercellular communication as early biological markers of mercuric chloride toxicity in MDCK cell line.
In this study, the early nephrotoxic potential of mercuric chloride (HgCl(2)) has been evaluated in vitro, by exposing a renal-derived cell system, the tubular epithelial Madin-Darby canine kidney (MDCK) cell line, to the presence of increasing HgCl(2) concentrations (0.1-100 microM) for different periods of time (from 4 to 72 h). As possible biological markers of the tubular-specific toxicity of HgCl(2) in exposed-MDCK cultures we analysed: (i) critical biochemical parameters related to oxidative stress conditions and (ii) gap-junctional function (GJIC). HgCl(2) cytotoxicity was evaluated by cell-density assay. The biochemical analysis of the pro-oxidant properties of the mercuric ion (Hg(2+)) was performed by evaluating the effect of the metal salt on the antioxidant status of the MDCK cells. The cell glutathione (GSH) content and the activity of glutathione peroxidase (Gpx) and catalase (Cat), two enzymes engaged in the H(2)O(2) degradation, were quantified. HgCl(2) influence on MDCK GJIC was analysed by the microinjection/dye-transfer assay. HgCl(2)-induced morphological changes in MDCK cells were also taken into account. Our results, proving that subcytotoxic (0.1-10 microM) HgCl(2) concentrations affect either the antioxidant defences of MDCK cells or their GJIC, indicate these critical functions as suitable biological targets of early mercury-induced tubular cell injury
Nutritional quality and yield of onion as affected by different application methods and doses of humic substances
Fertilization with humic substances (HS) has been proposed as target tool to improve crop production within a sustainable agriculture framework. The dose and application method are two factors that can influence the effect of HS on nutrient composition and productivity of onion. Therefore, our main objective was to assess the effect of each of the abovementioned factors, separately or interacting, on the quality and productivity of onion bulbs in a field test. The experimental design was completely randomized in a factorial 2 Ă 3, with two methods of application of HS and three different doses. The combined application method, immersion together with foliar pulverization, showed highest improvement of biomass and nutritional content of bulbs. However, while the intermediate dose of HS exerted greater increases on onion yield, productivity, carbohydrates and proteins levels in bulbs, mineral nutrient accumulation resulted especially when highest doses of HS were added. From a nutritional point of view, higher sweetness (from 113 to 149 mg gâ1 of soluble sugars in dry matter) and an improved P, K and Mg content of bulbs (4.00, 11.65 and 3.18 g kgâ1, respectively) in response to HS addition has been ascribed.Marcelle M. Bettoni received a grant from âLos CAPES y Coordenação do Programa de PĂłs-graduação em AgronomiaâProdução Vegetalâ from the Brazilian Government
Achievements in CTF3 and Commissioning status
The aim of the latest CLIC test facility CTF3, built at CERN by an international collaboration, is to prove the main feasibility issues of the CLIC two-beam acceleration technology. Several of the main goals have been already achieved in the past years, like the full-loading linac operation mode and the delay loop principle. During 2008 also the combiner ring concept has been experimentally proven and the recombined beam has been used to generate the RF power. In parallel in the fall of the year also the probe beam line commissioning had started
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