55 research outputs found
The birthplace and age of the isolated neutron star RX J1856.5-3754
X-ray observations unveiled various types of radio-silent Isolated Neutron
Stars (INSs), phenomenologically very diverse, e.g. the Myr old X-ray Dim INS
(XDINSs) and the kyr old magnetars. Although their phenomenology is much
diverse, the similar periods (P=2--10 s) and magnetic fields (~10^{14} G)
suggest that XDINSs are evolved magnetars, possibly born from similar
populations of supermassive stars. One way to test this hypothesis is to
identify their parental star clusters by extrapolating backward the neutron
star velocity vector in the Galactic potential. By using the information on the
age and space velocity of the XDINS RX J1856.5-3754, we computed backwards its
orbit in the Galactic potential and searched for its parental stellar cluster
by means of a closest approach criterion. We found a very likely association
with the Upper Scorpius OB association, for a neutron star age of 0.42+/-0.08
Myr, a radial velocity V_r^NS =67+/- 13$ km s^{-1}, and a present-time
parallactic distance d_\pi^NS = 123^{+11}_{-15} pc. Our result confirms that
the "true" neutron star age is much lower than the spin-down age (tau_{sd}=3.8
Myrs), and is in good agreement with the cooling age, as computed within
standard cooling scenarios. The mismatch between the spin-down and the
dynamical/cooling age would require either an anomalously large breaking index
(n~20) or a decaying magnetic field with initial value B_0 ~ 10^{14} G.
Unfortunately, owing to the uncertainty on the age of the Upper Scorpius OB
association and the masses of its members we cannot yet draw firm conclusions
on the estimated mass of the RX J1856.5-3754 progenitor.Comment: 6 pages, accepted for publication on Monthly Notices of the Royal
Astronomical Societ
Satellite galaxies in groups in the CIELO Project I: Gas removal from galaxies and its re-distribution in the intragroup medium
We study the impact of the environment on galaxies as they fall in and orbit in the potential well of a Local Group (LG) analogue, following them with high cadence. The analysis is performed on eight disc satellite galaxies from the CIELO suite of hydrodynamical simulations. All galaxies have stellar masses within the range [10 8.1 -109.56 ] M⊙h-1. We measure tidal torques, ram pressure, and specific star formation rates (sSFRs) as a function of time, and correlate them with the amount of gas lost by satellites along their orbits. Stronger removal episodes occur when the disc plane is oriented perpendicular to the direction of motion. More than one peripassage is required to significantly modify the orientations of the discs with respect to the orbital plane. The gas removed during the interaction with the central galaxies may also be found opposite to the direction of motion, depending on the orbital configuration. Satellites are not totally quenched when the galaxies reach their first peripassage and continue forming about 10 per cent of the final stellar mass after this event. The fraction of removed gas is found to be the product of the joint action of tidal torque and ram pressure, which can also trigger new star formation activity and subsequent supernova feedback.Fil: Rodríguez Moncada, Silvio Ribamar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Garcia Lambas, Diego Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba; ArgentinaFil: Padilla, Nelson David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Tissera, P.. Pontificia Universidad Católica de Chile; ChileFil: Bignone, Lucas Axel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Dominguez Tenreiro, Rosa. Pontificia Universidad Católica de Chile; ChileFil: Gonzalez, R.. Pontificia Universidad Católica de Chile; ChileFil: Pedrosa, Susana Elizabeth. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin
STAFNE BONE CYST IN THE ANTERIOR MANDIBLE: AN UNUSUAL LOCATION
To describe clinical features of the anterior Stafne bone cyst.
To supply radiologist a guide for diagnosis and classification of Stafne bone cyst
Interleukin-9 Overexpression and Th9 Polarization Characterize the Inflamed Gut, the Synovial Tissue, and the Peripheral Blood of Patients With Psoriatic Arthritis
Objective. To investigate the expression and tis- sue distribution of Th9-related cytokines in patients with psoriatic arthritis (PsA).
Methods. Quantitative gene expression analysis of Th1, Th17, and Th9 cytokines was performed in intestinal biopsy samples obtained from patients with PsA, HLA2B272positive patients with ankylosing spondylitis (AS), patients with Crohn’s disease (CD), and healthy controls. Expression and tissue distribu- tion of interleukin-23 (IL-23), IL-17, IL-22, IL-9, and IL-9 receptor (IL-9R) were evaluated by immunohisto- chemistry and confocal microscopy. Flow cytometry was used to study the frequency of Th9 cells among periph- eral blood, lamina propria, and synovial fluid mononuclear cells. The functional relevance of IL-9R expression on epithelial cells was assessed in functional in vitro studies. Th9 cells in synovial tissue from patients with PsA were also studied.
Results. Subclinical gut inflammation in PsA patients was characterized by a clear Th17 and Th22, but not Th1, polarized immune response. Unlike AS and CD, a strong and significant up-regulation of IL-9 was observed in PsA gut, especially among infiltrating mononuclear cells, high endothelial venules, and Pan- eth cells. IL-92positive mononuclear cells were demon- strated to be in large part Th9 cells. IL-9 overexpression was accompanied by significant Paneth cell hyperplasia. Paneth cells strongly overexpressed IL-9R, and stimula- tion of epithelial cells, isolated from PsA patients, with IL-9 resulted in overexpression of a-defensin 5 and IL-23p19. Peripheral and synovial expansion of a4b71 Th9 cells was also observed in patients with PsA. Increased expression of IL-9 and IL-9R was also found in synovial tissue.
Conclusion. Strong IL-9/Th9 polarization seems to be the predominant immunologic signature in patients in PsA
Adenoviral vaccine targeting multiple neoantigens as strategy to eradicate large tumors combined with checkpoint blockade
Turing patterns on networks
Turing patterns formed by activator-inhibitor systems on networks are
considered. The linear stability analysis shows that the Turing instability
generally occurs when the inhibitor diffuses sufficiently faster than the
activator. Numerical simulations, using a prey-predator model on a scale-free
random network, demonstrate that the final, asymptotically reached Turing
patterns can be largely different from the critical modes at the onset of
instability, and multistability and hysteresis are typically observed. An
approximate mean-field theory of nonlinear Turing patterns on the networks is
constructed.Comment: 4 pages, 4 figure
Complex evolution in genetic networks
A simple model of diffusively coupled genetic networks on a 1d lattice
is considered as a case study for characterizing complex unpredictable
dynamics in Lyapunov-stable spatially extended systems.
This dynamical regime, corresponding to transient evolution lasting
over times that grow exponentially with the system size, is shown to
be associated to the existence of a multifractal attractor in the
thermodynamic limit. Space-time averages of proper observables
exhibit robust statistical properties for finite, sufficiently
large samples
Transferring the financial risk of offering pharmaceutical product benefits from a large public health care provider organization in Argentina to a consortium of pharmaceutical companies
Transferencia de los riesgos económicos de ofrecer prestaciones por productos farmacéuticos de una gran empresa proveedora de asistencia sanitaria a un consorcio de compañías farmacéuticas
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