1,165 research outputs found
Electromagnetic emission of white dwarf binary mergers
It has been recently proposed that the ejected matter from white dwarf (WD)
binary mergers can produce transient, optical and infrared emission similar to
the "kilonovae" of neutron star (NS) binary mergers. To confirm this we
calculate the electromagnetic emission from WD-WD mergers and compare with
kilonova observations. We simulate WD-WD mergers leading to a massive, fast
rotating, highly magnetized WD with an adapted version of the
smoothed-particle-hydrodynamics (SPH) code Phantom. We thus obtain initial
conditions for the ejecta such as escape velocity, mass and initial position
and distribution. The subsequent thermal and dynamical evolution of the ejecta
is obtained by integrating the energy-conservation equation accounting for
expansion cooling and a heating source given by the fallback accretion onto the
newly-formed WD and its magneto-dipole radiation. We show that magnetospheric
processes in the merger can lead to a prompt, short gamma-ray emission of up to
erg in a timescale of - s. The bulk of the ejecta
initially expands non-relativistically with velocity and then it
accelerates to due to the injection of fallback accretion energy. The
ejecta become transparent at optical wavelengths around days
post-merger with a luminosity - erg s. The X-ray
emission from the fallback accretion becomes visible around -
day post-merger with a luminosity of erg s. We also predict
the post-merger time at which the central WD should appear as a pulsar
depending on the value of the magnetic field and rotation period.Comment: 12 pages, Accepted for publication in JCA
High-temperature anti-Invar behavior of gamma-Fe precipitates in Fe_xCu_(100-x) solid solutions: Ferromagnetic phases
High-temperature magnetization and neutron diffraction measurements on metastable Fe_xCu_(100-x) solid solutions have recently shown to imply that γ-Fe precipitates present ferromagnetic anti-Invar behavior. For this reason, we have studied the ferromagnetic phases of γ-Fe in moment-volume parameter space, using the general potential linearized-augmented plane-wave method and the fixed spin moment procedure in order to calculate the corresponding total energy. We find that only two ferromagnetic phases (one related to a low- spin state and the other to a high-spin state) can exist and even coexist in limited volume ranges (3.55-3.59 Å). Hence, our results provide a "revisited" version of the local spin density calculations used in the early article by Moruzzi [Phys. Rev. B 34, 1784 (1986)]. In addition, the fixed spin moment method-using an energy-moment-volume space representation-allows us to conclude that the high-spin state is the ground state of the gamma-Fe precipitates, as the anti-Invar behavior is an intrinsic property of these states. This simple scenario seems to adequately describe the perplexing phenomenology recently observed on Fe_xCu_(100-x) solid solutions
Strings at the bottom of the deformed conifold
We present solutions of the equations of motion of macroscopic F and D
strings extending along the non compact 4D sections of the conifold geometry
and winding around the internal directions. The effect of the Goldstone modes
associated with the position of the strings on the internal manifold can be
seen as a current on the string that prevents it from collapsing and allows the
possibility of static 4D loops. Its relevance in recent models of brane
inflation is discussed.Comment: 9+1 page
Chirping compact stars: gravitational radiation and detection degeneracy with binary systems A conceptual pathfinder for space-based gravitational-wave observatories
Compressible, Riemann S-type ellipsoids can emit gravitational waves (GWs)
with a chirp-like behavior (hereafter chirping ellipsoids, CELs). We show that
the GW frequency-amplitude evolution of CELs (mass ~M, radius
~km, polytropic equation of state with index ) is
indistinguishable from that emitted by double white dwarfs (DWDs) and by
extreme mass-ratio inspirals (EMRIs) composed of an intermediate-mass
(e.g.~) black hole and a planet-like (e.g.~)
companion, in a specific frequency interval within the detector sensitivity
band in which the GWs of all these systems are quasi-monochromatic. We estimate
that for reasonable astrophysical assumptions, the rates in the local Universe
of CELs, DWDs and EMRIs in the mass range considered here, are very similar,
posing a detection-degeneracy challenge for space-based GW detectors. The
astrophysical implications of this CEL-binary detection degeneracy by
space-based GW-detection facilities, are outlined.Comment: Submitted to Phys. Rev.
Training concerning the protection of animals used for experimentation scientific and educational purposes. Regulatory aspects
Resúmenes IV Congreso VetDoc de Docencia Veterinaria, León 2017 (6-7 de Julio)[ES] La utilización de animales para investigación y docencia con el objetivo de obtener información y datos relevantes para la ciencia ha generado una gran controversia ética desde finales del siglo XIX. Asumiendo la necesidad de utilizar animales para estos fines los paÃses europeos han desarrollado un amplio corpus legislativo ya que entre las disposiciones de la Unión Europea se encuentra la obligación de los Estados Miembros de aplicar la protección/Bienestar Animal en las polÃticas de investigación y desarrollo tecnológico
Binding site plasticity in viral PPxY Late domain recognition by the third WW domain of human NEDD4
The recognition of PPxY viral Late domains by the third WW domain of the HECT-E3 ubiquitin ligase
NEDD4 (hNEDD4-WW3) is essential for the completion of the budding process of numerous enveloped
viruses, including Ebola, Marburg, HTLV1 or Rabies. hNEDD4-WW3 has been validated as a promising
target for the development of novel host-oriented broad spectrum antivirals. Nonetheless, finding
inhibitors with good properties as therapeutic agents remains a challenge since the key determinants
of binding affinity and specificity are still poorly understood. We present here a detailed structural
and thermodynamic study of the interactions of hNEDD4-WW3 with viral Late domains combining
isothermal titration calorimetry, NMR structural determination and molecular dynamics simulations.
Structural and energetic differences in Late domain recognition reveal a highly plastic hNEDD4-WW3
binding site that can accommodate PPxY-containing ligands with varying orientations. These
orientations are mostly determined by specific conformations adopted by residues I859 and T866.
Our results suggest a conformational selection mechanism, extensive to other WW domains, and
highlight the functional relevance of hNEDD4-WW3 domain conformational flexibility at the binding
interface, which emerges as a key element to consider in the search for potent and selective inhibitors of
therapeutic interest.This research has been financed by grants BIO2009-13261-C02, BIO2012-39922-CO2 and
BIO2016-78746-C2-1-R from the Spanish Ministry of Education and Science (I.L.) including AEI/FEDER
EU funds, by CTQ2017-83810-R grant (F.J.B) and by BFU2014-53787-P, the IRB Barcelona and the BBVA
Foundation (M.J.M)
Incidents control in radiotherapy oncology
Primer pla de l'escut del monarca del s. XVI,
conservat i ubicat a la porta de la UB. Mesura
1,60 x 2,20 metre si és de pedra sorrenca
Evaluation of the bovine ATP-binding cassette subfamily A member 13 (ABCA13) as a potential biomarker for sensitive detection of animals with focal pathological forms of subclinical paratuberculosis
Trabajo presentado al: ICP 15th International Association for Paratuberculous, DublÃn, 12-16 Junio. 2022.Peer reviewe
Use of ATP-Binding cassette Subfamily A Member 13 (ABCA13) for sensitive detection of focal pathological forms of subclinical bovine paratuberculosis
14 páginas, 4 tablas, 3 figuras.Bovine paratuberculosis (PTB) is a chronic enteritis caused by Mycobacterium avium
subspecies paratuberculosis (Map) that causes a heavy economic impact worldwide.
Map infected animals can remain asymptomatic for years while transmitting the
mycobacteria to other members of the herd. Therefore, accurate detection of subclinically
infected animals is crucial for disease control. In a previous RNA-Seq study, we
identified several mRNAs that were overexpressed in whole blood of cows with different
PTB-associated histological lesions compared with control animals without detected
lesions. The proteins encoded by two of these mRNAs, ATP binding cassette subfamily
A member 13 (ABCA13) and Matrix Metallopeptidase 8 (MMP8) were significantly
overexpressed in whole blood of animals with focal histological lesions, the most frequent
pathological form in the subclinical stages of the disease. In the current study, the
potential of sensitive early diagnostic tools of commercial ELISAs, based on the detection
of these two biomarkers, was evaluated in serum samples of 704 Holstein Friesian cows
(566 infected animals and 138 control animals from PTB-free farms). For this evaluation,
infected animals were classified into three groups, according to the type of histological
lesions present in their gut tissues: focal (n = 447), multifocal (n = 59), and diffuse (n = 60).
The ELISA based on the detection of ABCA13 was successfully validated showing good
discriminatory power between animals with focal lesions and control animals (sensitivity
82.99% and specificity 80.43%). Conversely, the MMP8-based ELISA showed a poor
discriminatory power between the different histological groups and non-infected controls.
The ABCA13-based ELISA showed a higher diagnostic value (0.822) than the IDEXX
ELISA (0.517), the fecal bacterial isolation (0.523) and the real-time PCR (0.531) for the
detection of animals with focal lesions. Overall, our results indicate that this ABCA13
ELISA greatly improves the identification of subclinically infected animals with focal lesions
that are undetectable using current diagnostic methods.This study was part of the I+D+i project (RTI2018-
094192-R-C22) and was funded by the Spanish
MCIN/AEI/10.13039/501100011033/ Ministry of Science,
Innovation and the European Regional Development Funds
(FEDER Una manera de hacer Europa) and by the Gobierno
del Principado de Asturias, Regional funds PCTI 2021–
2023 (GRUPIN: IDI2021-000102) co-funded by FEDER. We
acknowledge the National Institute for Agricultural Research
(INIA) for the scholarships of CB-V (Ayuda CPD2016-0142
financiada por MCIN/AEI/ 10.13039/501100011033 y FSE El
FSE invierte en tu future) and MC.Peer reviewe
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