337 research outputs found
ESO 603-G21: A strange polar-ring galaxy
We present the results of B, V, R surface photometry of ESO603-G21 - a galaxy
with a possible polar ring. The morphological and photometric features of this
galaxy are discussed. The central round object of the galaxy is rather red and
presents a nearly exponential surface brightness distribution. This central
structure is surrounded by a blue warped ring or disk. The totality of the
observed characteristics (optical and NIR colors, strong color gradients, HI
and H_2 content, FIR luminosity and star-formation rate, rotation-curve shape,
global mass-to-luminosity ratio, the agreement with the Tully-Fisher relation,
etc.) shows that ESO603-G21 is similar to late-type spiral galaxies. We suppose
that morphological peculiarities and the possible existence of two large-scale
kinematically-decoupled subsystems in ESO603-G21 can be explained as being a
result of dissipative merging of two spiral galaxies or as a consequence of a
companion accretion onto a pre-existing spiral host.Comment: 8 pages, Astron. Astrophys, accepte
A first study of the galaxy HRG 2304 and its companion AM 1646-795 (NED01)
Aims. We report the first study of the peculiar ring-like galaxy HRG 2304
(NED02),which was previously classified as a ring galaxy with an elliptical
smooth ring. This object was selected to prove that it is a candidate for the
Solitaire-type ring galaxies in an early stage of ring formation. The main goal
of this work is to provide the spectral characteristics of the current object
and its companion AM 1646-795 (NED01). Methods. The study is based on
spectroscopic observations in the optical band to highlight the characteristics
of this interacting galaxy. To investigate the star formation history of HRG
2304 we used the stellar population synthesis code STARLIGHT. The direct V and
B broad band images were used to enhance some fine structures. Results. Along
the entire long-slit signal, the spectra of HRG 2304 and its companion resemble
that of an early-type galaxy. We estimated a heliocentric systemic redshift of
z = 0.0415, corresponding to heliocentric velocities of 12449 km s-1 for HRG
2304 (NED02) and 12430 km s-1 for AM1646-795 (NED01). The spatial variation in
the contribution of the stellar population components for both objects are
dominated by an old stellar population 2x10^9 < t < 13x10^9 yr. The observed
radial-velocity distribution and the fine structures around HRG 2304 suggest an
ongoing tidal interaction of both galaxies. Conclusions.The spectroscopic
results and the morphological peculiarities of HRG 2304 can be adequately
interpreted as an ongoing interaction with the companion galaxy. Both galaxies
are early-type, the companion is elliptical, and the smooth distribution of the
material around HRG 2304 and its off-center nucleus in the direction of
AM1646-795 (NED01) characterize HRG 2304 as a Solitaire-type galaxy candidate
in an early stage of ring formation.Comment: Accepted for publication in Astronomy and Astrophysics, 9 pages, 10
figures and 3 table
Testing the Newton second law in the regime of small accelerations
It has been pointed out that the Newtonian second law can be tested in the very small acceleration regime by using the combined movement of the Earth and Sun around the Galactic center of mass. It has been shown that there are only two brief intervals during the year in which the experiment can be completed, which correspond to only two specific spots on the Earth surface. An alternative experimental setup is presented to allow the measurement to be made on Earth at any location and at any time.It has been pointed out that the Newtonian second law can be tested in the very small acceleration regime by using the combined movement of the Earth and Sun around the Galactic center of mass. It has been shown that there are only two brief intervals during the year in which the experiment can be completed, which correspond to only two specific spots on the Earth surface. An alternative experimental setup is presented to allow the measurement to be made on Earth at any location and at any time
Prospección de mercado de hortalizas bajo producción integrada en cuatro ciudades de la Octava Región de Chile
Published by Asociación de Economistas Agrarios de Chilewillingness to purchase, vegetables, integrated production, Agribusiness, Consumer/Household Economics, Marketing,
FM 047-02: a collisional pair of galaxies with a ring
Aims. We investigate the nature of the galaxy pair FM 047-02, which has been
proposed as an archetype of the Solitaire types of peculiar (collisional) ring
galaxies. Methods. The study is based on long-slit spectrophotometric data in
the range of 3500-9500 angstrons obtained with the Gemini Multi-ObjectComment: 07 pages, 06 figures, 02 tables. arXiv admin note: text overlap with
arXiv:1206.071
SLC30A3 (ZnT3) Oligomerization by Dityrosine Bonds Regulates Its Subcellular Localization and Metal Transport Capacity
Non-covalent and covalent homo-oligomerization of membrane proteins regulates their subcellular localization and function. Here, we described a novel oligomerization mechanism affecting solute carrier family 30 member 3/zinc transporter 3 (SLC30A3/ZnT3). Oligomerization was mediated by intermolecular covalent dityrosine bonds. Using mutagenized ZnT3 expressed in PC12 cells, we identified two critical tyrosine residues necessary for dityrosine-mediated ZnT3 oligomerization. ZnT3 carrying the Y372F mutation prevented ZnT3 oligomerization, decreased ZnT3 targeting to synaptic-like microvesicles (SLMVs), and decreased resistance to zinc toxicity. Strikingly, ZnT3 harboring the Y357F mutation behaved as a “gain-of-function” mutant as it displayed increased ZnT3 oligomerization, targeting to SLMVs, and increased resistance to zinc toxicity. Single and double tyrosine ZnT3 mutants indicate that the predominant dimeric species is formed between tyrosine 357 and 372. ZnT3 tyrosine dimerization was detected under normal conditions and it was enhanced by oxidative stress. Covalent species were also detected in other SLC30A zinc transporters localized in different subcellular compartments. These results indicate that covalent tyrosine dimerization of a SLC30A family member modulates its subcellular localization and zinc transport capacity. We propose that dityrosine-dependent membrane protein oligomerization may regulate the function of diverse membrane protein in normal and disease states
Towards Socially and Emotionally Believable ICT Interfaces
In order to realize an artificial intelligence focused on human needs, it is necessary to identify the interactional characteristics that describe human mood, social behavior, beliefs, and experiences. The cross-modal analysis of communicative macro-signals represents the first step in this direction. The second step requires the definition of adequate mathematical representations of these signals to validate them perceptively (on the human side) and computationally
Gender identification through handwriting: An online approach
The present study was designed to identify writer's gender trough online handwriting and drawing analysis. Two groups - one of 126 males (mean age 24.65, SD=2.45) and the other of 114 females (mean age 24.51, SD=2.50) participants were recruited in the experiment. They were asked to perform seven writing and drawing tasks utilizing a digitizing tablet and a special writing device. Seventeen writing features grouped into five categories have been considered. The experiment's results show that the set of considered features enable to discriminate between male and female writers investigating their performance while copying a house drawing (task 2), writing words in capital letters (task 3) and writing a complete sentence in cursive letters (task 7), in particular focusing on Ductus (number of strokes) and Time categories of writing features
Gamma distribution function to understand anaerobic digestion kinetics:Kinetic constants are not constant
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