2,306 research outputs found
Forming first-ranked early-type galaxies through hierarchical dissipationless merging
We have developed a computationally competitive N-body model of a
previrialized aggregation of galaxies in a flat LambdaCDM universe to assess
the role of the multiple mergers that take place during the formation stage of
such systems in the configuration of the remnants assembled at their centres.
An analysis of a suite of 48 simulations of low-mass forming groups (of about
1E13 solar masses) demonstrates that the gravitational dynamics involved in
their hierarchical collapse is capable of creating realistic first-ranked
galaxies without the aid of dissipative processes. Our simulations indicate
that the brightest group galaxies (BGGs) constitute a distinct population from
other group members, sketching a scenario in which the assembly path of these
objects is dictated largely by the formation of their host system. We detect
significant differences in the distribution of Sersic indices and total
magnitudes, as well as a luminosity gap between BGGs and the next brightest
galaxy that is positively correlated with the total luminosity of the parent
group. Such gaps arise from both the grow of BGGs at the expense of lesser
companions and the decrease in the relevance of second-ranked objects in equal
measure. This results in a dearth of intermediate-mass galaxies which explains
the characteristic central dip detected in their luminosity functions in
dynamically young galaxy aggregations. The fact that the basic global
properties of our BGGs define a thin mass fundamental plane strikingly similar
to that followed giant early-type galaxies in the local universe reinforces
confidence in the results obtained.Comment: 25 pages, 14 figures, 3 tables. Accepted to MNRA
CG J1720-67.8: A Detailed Analysis of Optical and Infrared Properties of a New Ultracompact Group of Galaxies
We present here optical spectroscopy and BVRJHK(s) photometry of the recently
discovered ultra-compact group of galaxies CG J1720-67.8. This work represents
a considerable extension of the preliminary results we presented in a previous
paper. Despite the complicated morphology of the group, a quantitative
morphological classification of the three brightest members of the group is
attempted based on photometric analysis. We find that one galaxy is consistent
with a morphological type S0, while the other two are most probably late-type
spirals that are already losing their identity due tothe interaction process.
Information on the star formation activity and dust content derived from both
spectroscopic data and optical and near-infrared colors are complemented with a
reconstruction of far-infrared (FIR) maps from IRAS raw data. Enhanced star
formation activity is revealed in all the group's members, including the
early-type galaxy and the extended tidal tail, along which several tidal dwarf
galaxy candidates are identified. The metallicity of the gaseous component is
investigated and photoionization models are applied to the three main galaxies
of the group, while a detailed study of the tidal dwarf candidates will appear
in a companion paper. Subsolar metal abundances are found for all the three
galaxies, the highest values being shown by the early-type galaxy (Z ~ 0.5
Zsolar).Comment: Accepted for publication in The Astrophysical Journa
Optimizing CIGB-300 intralesional delivery in locally advanced cervical cancer
Background:We conducted a phase 1 trial in patients with locally advanced cervical cancer by injecting 0.5 ml of the CK2-antagonist CIGB-300 in two different sites on tumours to assess tumour uptake, safety, pharmacodynamic activity and identify the recommended dose.Methods:Fourteen patients were treated with intralesional injections containing 35 or 70 mg of CIGB-300 in three alternate cycles of three consecutive days each before standard chemoradiotherapy. Tumour uptake was determined using 99 Tc-radiolabelled peptide. In situ B23/nucleophosmin was determined by immunohistochemistry.Results:Maximum tumour uptake for CIGB-300 70-mg dose was significantly higher than the one observed for 35 mg: 16.1±8.9 vs 31.3±12.9 mg (P=0.01). Both, AUC 24h and biological half-life were also significantly higher using 70 mg of CIGB-300 (P<0.001). Unincorporated CIGB-300 diffused rapidly to blood and was mainly distributed towards kidneys, and marginally in liver, lungs, heart and spleen. There was no DLT and moderate allergic-like reactions were the most common systemic side effect with strong correlation between unincorporated CIGB-300 and histamine levels in blood. CIGB-300, 70 mg, downregulated B23/nucleophosmin (P=0.03) in tumour specimens.Conclusion:Intralesional injections of 70 mg CIGB-300 in two sites (0.5 ml per injection) and this treatment plan are recommended to be evaluated in phase 2 studies.Fil: Sarduy, M. R.. Medical-surgical Research Center; CubaFil: García, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Coca, M. A.. Clinical Investigation Center; CubaFil: Perera, A.. Clinical Investigation Center; CubaFil: Torres, L. A.. Clinical Investigation Center; CubaFil: Valenzuela, C. M.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Baladrón, I.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Solares, M.. Hospital Materno Ramón González Coro; CubaFil: Reyes, V.. Center For Genetic Engineering And Biotechnology Havana; CubaFil: Hernández, I.. Isotope Center; CubaFil: Perera, Y.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Martínez, Y. M.. Medical-surgical Research Center; CubaFil: Molina, L.. Medical-surgical Research Center; CubaFil: González, Y. M.. Medical-surgical Research Center; CubaFil: Ancízar, J. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Prats, A.. Clinical Investigation Center; CubaFil: González, L.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Casacó, C. A.. Clinical Investigation Center; CubaFil: Acevedo, B. E.. Centro de Ingeniería Genética y Biotecnología; CubaFil: López Saura, P. A.. Centro de Ingeniería Genética y Biotecnología; CubaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes; ArgentinaFil: Gómez, R.. Elea Laboratories; ArgentinaFil: Perea Rodríguez, S. E.. Center For Genetic Engineering And Biotechnology Havana; Cuba. Centro de Ingeniería Genética y Biotecnología; Cub
Enfermedades congénitas e identificación
X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200
Spitzer Infrared Spectrograph Observations of Magellanic Cloud Planetary Nebulae: the nature of dust in low metallicity circumstellar ejecta
We present 5 - 40 micron spectroscopy of 41 planetary nebulae (PNe) in the
Magellanic Clouds, observed with the Infrared Spectrograph on board the Spitzer
Space Telescope. The spectra show the presence of a combination of nebular
emission lines and solid-state features from dust, superimposed on the thermal
IR continuum.
By analyzing the 25 LMC and 16 SMC PNe in our sample we found that the IR
spectra of 14 LMC and 4 SMC PNe are dominated by nebular emission lines, while
the other spectra show solid-state features. We observed that the solid-state
features are compatible with carbon-rich dust grains (SiC, polycyclic aromatic
hydrocarbons (PAHs), etc.) in most cases, except in three PNe showing
oxygen-rich dust features. The frequency of carbonaceous dust features is
generally higher in LMC than in SMC PNe.
The spectral analysis allowed the correlations of the dust characteristics
with the gas composition and morphology, and the properties of the central
stars. We found that: 1) all PNe with carbonaceous dust features have C/O>1,
none of these being bipolar or otherwise highly asymmetric; 2) all PNe with
oxygen-rich dust features have C/O<1, with probable high mass progenitors if
derived from single-star evolution (these PNe are either bipolar or highly
asymmetric); 3) the dust temperature tracks the nebular and stellar evolution;
and 4) the dust production efficiency depends on metallicity, with low
metallicity environments not favoring dust production.Comment: The Astrophysical Journal, in pres
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