2,439 research outputs found
Non-canonical NFκB activation promotes chemokine expression in podocytes
TNF-like weak inducer of apoptosis (TWEAK) receptor Fn14 is expressed by podocytes and Fn14 deficiency protects from experimental proteinuric kidney disease. However, the downstream effectors of TWEAK/Fn14 in podocytes are poorly characterized. We have explored TWEAK activation of non-canonical NFκB signaling in cultured podocytes. In cultured podocytes, TWEAK increased the expression of the chemokines CCL21, CCL19 and RANTES in a time-dependent manner. The inhibitor of canonical NFκB activation parthenolide inhibited the CCL19 and the early RANTES responses, but not the CCL21 or late RANTES responses. In this regard, TWEAK induced non-canonical NFκB activation in podocytes, characterized by NFκB2/p100 processing to NFκB2/p52 and nuclear migration of RelB/p52. Silencing by a specific siRNA of NIK, the upstream kinase of the non-canonical NFκB pathway, prevented CCL21 upregulation but did not modulate CCL19 or RANTES expression in response to TWEAK, thus establishing CCL21 as a non-canonical NFκB target in podocytes. Increased kidney Fn14 and CCL21 expression was also observed in rat proteinuric kidney disease induced by puromycin, and was localized to podocytes. In conclusion, TWEAK activates the non-canonical NFκB pathway in podocytes, leading to upregulation of CCL21 expression. The non-canonical NFκB pathway should be explored as a potential therapeutic target in proteinuric kidney disease.Grants support: FEDER funds and FIS ISCIII-RETIC REDinREN RD12/0021, PI15/00298, PI13/00047,
CP14/00133, CP12/03262, Spanish Society of Nephrology, FRIAT-IRSIN, Comunidad de Madrid (CIFRA S2010/
BMD-2378), CYTED IBERERC, Programa Intensificación Actividad Investigadora (ISCIII) to AO, Miguel Servet
to MDSN and ABS and FIS to LVR and LG
Entropy spectrum of a Kerr anti-de Sitter black hole
The entropy spectrum of a spherically symmetric black hole was derived
without the quasinormal modes in the work of Majhi and Vagenas. Extending this
work to rotating black holes, we quantize the entropy and the horizon area of a
Kerr anti-de Sitter black hole by two methods. The spectra of entropy and area
are obtained via the Bohr-Sommerfeld quantization rule and the adiabatic
invariance in the first way. By addressing the wave function of emitted
(absorbed) particles, the entropy and the area are quantized in the second one.
Both results show that the entropy and the area spectra are equally spaced.Comment: Accepted for publication in The European Physical Journal C, Volume
72, Issue
Gastric Prolapse with Pseudocysts Following Laparoscopic Adjustable Gastric Banding
Nonpancreatic pseudocysts may be associated with gastric prolapse in patients who have undergone laparoscopic adjustable gastric banding
Magnetic proximity effect features in antiferromagnetic/ferrimagnetic core-shell nanoparticles
A study of "inverted" core-shell, MnO/γ-Mn2O3, nanoparticles is presented. Crystal and magnetic structures and characteristic sizes have been determined by neutron diffraction for the antiferromagnetic core (MnO) and the ferrimagnetic shell (γ-Mn2O3). Remarkably, while the MnO core is found to have a TN not far from its bulk value, the magnetic order of the γ-Mn2O3 shell is stable far above TC, exhibiting two characteristic temperatures, at T~ 40 K [TC(γ-Mn2O3)] and at T~120 K [~ TN(MnO)]. Magnetization measurements are consistent with these results. The stabilization of the shell moment up to TN of the core can be tentatively attributed to core-shell exchange interactions, hinting at a possible magnetic proximity effect
Evidence for chiral superconductivity on a silicon surface
Sn adatoms on a Si(111) substrate with 1/3 monolayer coverage form a
two-dimensional triangular adatom lattice with one unpaired electron per site
and an antiferromagnetic Mott insulating state. The Sn layers can be modulation
hole-doped and metallized using heavily-doped -type Si(111) substrates, and
become superconducting at low temperatures. While the pairing symmetry of the
superconducting state is currently unknown, the combination of repulsive
interactions and frustration inherent to the triangular adatom lattice opens up
the possibility for a chiral order parameter. Here, we study the
superconducting state of Sn/Si(111) using scanning tunneling
microscopy/spectroscopy and quasi-particle interference imaging. We find
evidence for a doping-dependent with a fully gapped order parameter, the
presence of time-reversal symmetry breaking, and a strong enhancement of the
zero-bias conductance near the edges of the superconducting domains. While each
individual piece of evidence could have a more mundane interpretation, our
combined results suggest the tantalizing possibility that Sn/Si(111) is an
unconventional chiral d-wave superconductor
Measures of Similarity Between Objects Based on Qualitative Shape Descriptions
A computational approach for comparing qualitative shape descriptions
(QSDs) of objects within digital images is presented. First, the dissimilarity
of qualitative features of shape is measured: (i) intuitively using conceptual
neighbourhood diagrams; and (ii) mathematically using interval distances.
Then, a similarity measure between QSDs is defined and tested using
images of different categories of the MPEG-7-CE-Shape-1 library, images
of tiles used to build mosaics, and a collection of Clipart images. The
results obtained show the effectiveness of the similarity measure defined,
which is invariant to translations, rotations and scaling, and which implicitly
manages deformation of shape parts and incompleteness
The Mass-Metallicity relation explored with CALIFA: I. Is there a dependence on the star formation rate?
We present the results on the study of the global and local M-Z relation
based on the first data available from the CALIFA survey (150 galaxies). This
survey provides integral field spectroscopy of the complete optical extent of
each galaxy (up to 2-3 effective radii), with enough resolution to separate
individual HII regions and/or aggregations. Nearly 3000 individual HII
regions have been detected. The spectra cover the wavelength range between
[OII]3727 and [SII]6731, with a sufficient signal-to-noise to derive the oxygen
abundance and star-formation rate associated with each region. In addition, we
have computed the integrated and spatially resolved stellar masses (and surface
densities), based on SDSS photometric data. We explore the relations between
the stellar mass, oxygen abundance and star-formation rate using this dataset.
We derive a tight relation between the integrated stellar mass and the
gas-phase abundance, with a dispersion smaller than the one already reported in
the literature (0.07 dex). Indeed, this
dispersion is only slightly larger than the typical error derived for our
oxygen abundances. However, we do not find any secondary relation with the
star-formation rate, other than the one induced due to the primary relation of
this quantity with the stellar mass. We confirm the result using the 3000
individual HII regions, for the corresponding local relations.
Our results agree with the scenario in which gas recycling in galaxies, both
locally and globally, is much faster than other typical timescales, like that
of gas accretion by inflow and/or metal loss due to outflows. In essence,
late-type/disk dominated galaxies seem to be in a quasi-steady situation, with
a behavior similar to the one expected from an instantaneous
recycling/closed-box model.Comment: 19 Pages, 8 figures, Accepted for Publishing in Astronomy and
Astrophysics (A&A
Stellar Population gradients in galaxy discs from the CALIFA survey
While studies of gas-phase metallicity gradients in disc galaxies are common,
very little has been done in the acquisition of stellar abundance gradients in
the same regions. We present here a comparative study of the stellar
metallicity and age distributions in a sample of 62 nearly face-on, spiral
galaxies with and without bars, using data from the CALIFA survey. We measure
the slopes of the gradients and study their relation with other properties of
the galaxies. We find that the mean stellar age and metallicity gradients in
the disc are shallow and negative. Furthermore, when normalized to the
effective radius of the disc, the slope of the stellar population gradients
does not correlate with the mass or with the morphological type of the
galaxies. Contrary to this, the values of both age and metallicity at 2.5
scale-lengths correlate with the central velocity dispersion in a similar
manner to the central values of the bulges, although bulges show, on average,
older ages and higher metallicities than the discs. One of the goals of the
present paper is to test the theoretical prediction that non-linear coupling
between the bar and the spiral arms is an efficient mechanism for producing
radial migrations across significant distances within discs. The process of
radial migration should flatten the stellar metallicity gradient with time and,
therefore, we would expect flatter stellar metallicity gradients in barred
galaxies. However, we do not find any difference in the metallicity or age
gradients in galaxies with without bars. We discuss possible scenarios that can
lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&
Allergy education and training for physicians.
The increasing prevalence of allergic diseases has placed a significant burden on global healthcare and society as whole. This has necessitated a rapid development of "allergy" as a specialist area. However, as allergy is so common and, for most, relatively easy to diagnose and control, all clinicians need to have basic knowledge and competence to manage mild disease and recognize when referral is required. The allergology specialty has not yet been recognized in many countries and even where allergy is fully recognized as a specialty, the approach to training in allergy differs significantly. In the light of recent developments in allergy diagnosis and management, there is an urgent need to harmonize core competences for physicians, as well as the standardization of core principles for medical education and post-graduate training in allergy. All physicians and allied health professionals must appreciate the multidisciplinary team (MDT) approach to allergy, which is key to achieving the highest standards in holistic care. Due to worldwide variation in resources and personnel, some MDT roles will need to be absorbed by the treating physician or other healthcare professionals. We draw particular attention to the role of psychological input for all allergy patients, dietetic input in the case of food allergy and patient education to support all patients in the supported self-management of their condition on a daily basis. A strong appreciation of these multidisciplinary aspects will help physicians provide quality patient-centered care. We consider that harmonization of allergy components within undergraduate curricula is crucial to ensure all physicians develop the appropriate allergy-related knowledge and skills, particularly in light of inconsistencies seen in the primary care management of allergy. This review from the World Allergy Organization (WAO) Education and Training Committee also outlines allergy-related competences required of physicians working with allergic patients and provides recommendations to promote harmonization of allergy training and practice worldwide
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