1,487 research outputs found
The Calar Alto Legacy Integral Field Area Survey: spatial resolved properties
We present the analysis performed using the pyPipe3D pipeline for the 895
galaxies that comprises the eCALIFA data release Sanchez et al. submitted, data
with a significantly improved spatial resolution (1.0-1.5"/FWHM). We include a
description of (i) the analysis performed by the pipeline, (ii) the adopted
datamodel for the derived spatially resolved properties and (iii) the catalog
of integrated, characteristics and slope of the radial gradients for a set of
observational and physical parameters derived for each galaxy. We illustrate
the results of the analysis (i) using the NGC\,2906 as an archetypal galaxy,
showing the spatial distribution of the different derived parameters and
exploring in detail the properties of the ionized gas, and (ii) showing
distribution of the spatial resolved ionized gas across the classical
[OIII]/H vs. [NII]/H for the whole galaxy sample. In general our
results agree with previous published ones, however, tracing radial patterns
and segregating individual ionized structures is improved when using the
current dataset. All the individual galaxy dataproducts and the catalog
discussed along this article are distributed as part of the eCALIFA data
release http://ifs.astroscu.unam.mx/CALIFA_WEB/public_html/Comment: 47 pages, 8 tables, 9 figures, submitted the 12th of April 2023 to
RMxA
Volatile compounds secreted by Brindley’s glands of adult Triatoma infestans:identification and biological activity of previously unidentified compounds
Volatile emissions of adult male Triatoma infestans were collected on non-polar SPME fibers and analyzed by
gas chromatography linked to a mass spectrometer. A complex mixture of 16 short-chain esters and acids were identified.
The composition of short-chain aliphatic acids (ethanoic to nonanoic acids) was similar to previously reported results. The most abundant aliphatic acid was 2-methylpropanoic acid, constituting 18% of the total volatile content. Also abundant were the esters 2- and 3-methylbutyl 2-methylpropanoate, which constituted 30% and 22%, respectively, of the total volatile content. A similar pattern of compounds was observed in the volatiles secreted by dissected male Brindley’s glands; however,
in this case, 2- and 3-methylbutan-1-ol were detected which were not found in live insect volatile emissions. Large variability in volatile composition was also observed among the glands excised from different insects. Electroantennographic (EAG) evaluation of the components of Brindley’s gland showed significant responses for 2- and 3-methylbutyl 2-methylpropanoate compared to controls. The mixture of volatiles secreted by excised Brindley’s glands and the isolated 2- and 3-methylbutyl 2-methylpropanoate had repellent effects on both male and female T. infestans, possibly associated with a defensive strategy
Rectangular core-collapse supernova remnants: application to Puppis A
Core-collapse supernova remnants are the gaseous nebulae of galactic
interstellar media (ISM) formed after the explosive death of massive stars.
Their morphology and emission properties depend both on the surrounding
circumstellar structure shaped by the stellar wind-ISM interaction of the
progenitor star and on the local conditions of the ambient medium. In the warm
phase of the Galactic plane (n = 1/cm3, T = 8000 K), an organised magnetic
field of strength 7 microG has profound consequences on the morphology of the
wind bubble of massive stars at rest. In this paper we show through 2.5D
magneto-hydrodynamical simulations, in the context of a Wolf-Rayet-evolving 35
Mo star, that it affects the development of its supernova remnant. When the
supernova remnant reaches its middle age (15 to 20 kyr), it adopts a tubular
shape that results from the interaction between the isotropic supernova ejecta
and the anisotropic, magnetised, shocked stellar progenitor bubble into which
the supernova blast wave expands. Our calculations for non-thermal emission,
i.e. radio synchrotron and inverse Compton radiation, reveal that such
supernova remnants can, due to projection effects, appear as rectangular
objects in certain cases. This mechanism for shaping a supernova remnant is
similar to the bipolar and elliptical planetary nebula production by wind-wind
interaction in the low-mass regime of stellar evolution. If such a rectangular
core-collapse supernova remnant is created, the progenitor star must not have
been a runaway star. We propose that such a mechanism is at work in the shaping
of the asymmetric core-collapse supernova remnant Puppis A.Comment: Accepted at MNRA
Tuning a Resonance in the Fock Space: Optimization of Phonon Emission in a Resonant Tunneling Device
Phonon-assisted tunneling in a double barrier resonant tunneling device can
be seen as a resonance in the electron-phonon Fock space which is tuned by the
applied voltage. We show that the geometrical parameters can induce a symmetry
condition in this space that can strongly enhance the emission of longitudinal
optical phonons. For devices with thin emitter barriers this is achieved by a
wider collector's barrier.Comment: 4 pages, 3 figures. Figure 1 changed, typos correcte
Constituent Model of Extremal non-BPS Black Holes
We interpret extremal non-BPS black holes in four dimensions as threshold
bound states of four 1/2-BPS constituents. We verify the no-force condition for
each of the primitive constituents in the probe approximation. Our computations
are for a seed solution with charges and equal -fields, but
symmetries extend the result to any U-dual frame. We make the constituent model
for the system explicit, and also discuss a duality frame where the
constituents are branes at angles. We demonstrate stability of the
constituent model in the weak coupling description of the constituent D-branes.
We discuss the relation between the BPS and non-BPS branches of configuration
space.Comment: 29 pages; v2. references adde
A replication study confirms the association of TNFSF4 (OX40L) polymorphisms with systemic sclerosis in a large European cohort
<p><b>Objectives</b> The aim of this study was to confirm the influence of TNFSF4 polymorphisms on systemic sclerosis (SSc) susceptibility and phenotypic features.</p>
<p><b>Methods</b> A total of 8 European populations of Caucasian ancestry were included, comprising 3014 patients with SSc and 3125 healthy controls. Four genetic variants of TNFSF4 gene promoter (rs1234314, rs844644, rs844648 and rs12039904) were selected as genetic markers.</p>
<p><b>Results</b> A pooled analysis revealed the association of rs1234314 and rs12039904 polymorphisms with SSc (OR 1.15, 95% CI 1.02 to 1.31; OR 1.18, 95% CI 1.08 to 1.29, respectively). Significant association of the four tested variants with patients with limited cutaneous SSc (lcSSc) was revealed (rs1234314 OR 1.22, 95% CI 1.07 to 1.38; rs844644 OR 0.91, 95% CI 0.83 to 0.99; rs844648 OR 1.10, 95% CI 1.01 to 1.20 and rs12039904 OR 1.20, 95% CI 1.09 to 1.33). Association of rs1234314, rs844648 and rs12039904 minor alleles with patients positive for anti-centromere antibodies (ACA) remained significant (OR 1.23, 95% CI 1.10 to 1.37; OR 1.12, 95% CI 1.01 to 1.25; OR 1.22, 95% CI 1.07 to 1.38, respectively). Haplotype analysis confirmed a protective haplotype associated with SSc, lcSSc and ACA positive subgroups (OR 0.88, 95% CI 0.82 to 0.96; OR 0.88, 95% CI 0.80 to 0.96; OR 0.86, 95% CI 0.77 to 0.97, respectively) and revealed a new risk haplotype associated with the same groups of patients (OR 1.14, 95% CI 1.03 to 1.26; OR 1.20, 95% CI 1.08 to 1.35; OR 1.23, 95% CI 1.07 to 1.42, respectively).</p>
<p><b>Conclusions</b> The data confirm the influence of TNFSF4 polymorphisms in SSc genetic susceptibility, especially in subsets of patients positive for lcSSc and ACA.</p>
- …