503 research outputs found
El aceite de oliva extra virgen y su fracción polifenólica previenen la respuesta inflamatoria y el daño articular en un modelo de artritis experimental en murino
The consumption of EVOO in Mediterranean countries has shown beneficial effects. A wide range of evidence indicates that the phenolic compounds present in EVOO are endowed with anti-inflammatory properties. In this work, we evaluated the effects of dietary EVOO and treatment with its phenolic extract (PE) in a model of RA, the collagen-induced arthritis (CIA) in mice. On day 0, DBA-1/J mice were immunized with bovine collagen type II (CII). On day 21, the mice received a booster injection. We have demonstrated that EVOO and its PE decreases joint edema, cell migration, cartilage degradation and bone erosion. Our data indicate that dietary EVOO and PE treatment inhibit JNK, p38 and signal transducer and STAT-3. In addition, both EVOO and PE decrease NF-κB translocation leading to the down-regulation of the arthritic process. These results support the interest of natural diet components in the development of therapeutic products for arthritic conditions.El consumo de Aceite de oliva virgen extra (AOVE) en los países mediterráneos ha demostrado tener efectos beneficiosos. Una amplia gama de pruebas indica que los compuestos fenólicos presentes en el AOVE tienen propiedades anti-inflamatorias. En este trabajo, se evaluaron los efectos de AOVE y el tratamiento en dieta de su fracción polifenólica (FP) en un modelo de la artritis reumatoide inducida por colágeno (CIA) en ratones. En el día 0, los ratones DBA-1/J se inmunizaron con colágeno bovino tipo II (CII). En el día 21, los ratones recibieron una inyección de refuerzo. Hemos demostrado que el AOVE y su FP disminuyen conjuntamente el edema, la migración celular, la degradación del cartílago y erosión ósea. Nuestros datos indican que la dieta con AOVE y el tratamiento con FP inhiben JNK, p38 y el transductor de señal y activador de la transcripción 3 (STAT-3). Además, tanto el AOVE como la FP disminuyen la translocación NF-κB que conduce a la mejora del proceso artrítico. Estos resultados apoyan el interés de una dieta con componentes naturales y el desarrollo de productos terapéuticos para desordenes artríticos
Structure of a complex carbonate aquifer by magnetic, gravity and TDEM prospecting in the Jaén area, Southern Spain
Knowledge of aquifer geometry is essential for efficient and sustainable groundwater management, particularly in carbonate aquifers due to uncertainties inherent to karstic systems. The geological structure and hydrogeological continuity of Los Chotos-Sazadilla-Los Nacimientos and La Serreta-Gante-Cabeza Montosa carbonate aquifers (Jaén; SE Spain) have been established through structural measurements, geophysical prospecting –magnetic, gravity and time-domain electromagnetics (TDEM)– and the study of piezometric levels. Yet the scarce hydrogeological data, the complexity of the tectonic structure and the presence of Plio-Quaternary rocks covering the highly permeable carbonate rocks make it difficult to establish a robust conceptual hydrogeological model of the aquifer. This study focuses on an area where hydrogeological disconnection between the two aquifers was traditionally assumed, given the diapiric emplacement of low permeable rocks between them. The new geophysical data demonstrate connection between aquifers that implies greater groundwater reserves than previously supposed. This field example supports the suitability of the combined use of electromagnetic methods with gravity and magnetic research that have been poorly combined up to recent times for hydrogeological studies
Experimental and theoretical assessment of native oxide in the superconducting TaN
In this manuscript, we show through an experimental-computational proof of
concept the native oxide formation into superconducting TaN films. First, TaN
was synthesized at an ultra-high vacuum system by reactive pulsed laser
deposition and characterized in situ by X-ray photoelectron spectroscopy. The
material was also characterized ex situ by X-ray diffraction, transmission
electron microscopy, and the four-point probe method. It was detected that TaN
contained considerable oxygen impurities (up to 26 %O) even though it was grown
in an ultra-high vacuum chamber. Furthermore, the impurified TaN evidence a
face-centered cubic crystalline structure only and exhibits superconductivity
at 2.99 K. To understand the feasibility of the native oxide in TaN, we study
the effect of incorporating different amounts of O atoms in TaN using ab-initio
calculations. A thermodynamic stability analysis shows that a TaOxN1-x model
increases its stability as oxygen is added, demonstrating that oxygen may
always be present in TaN, even when obtained at ultra-high vacuum conditions.
All analyzed models exhibit metallic behavior. Charge density difference maps
reveal that N and O atoms have a higher charge density redistribution than Ta
atoms. The electron localization function maps and line profiles indicate that
Ta-O and Ta-N bonds are mainly ionic. As expected, stronger ionic behavior is
observed in the Ta-O bonds due to the electronegativity difference between O
and N atoms. Recent evidence points to superconductivity in bulk TaO,
confirming the asseverations of superconductivity in our samples. The results
discussed here highlight the importance of considering native oxide when
reporting superconductivity in TaN films since the TaO regions formed in the
compound may be key to understanding the different critical temperatures
reported in the literature.Comment: 23 pages, 7 figure
Real-Time Path Planning Based on Harmonic Functions under a Proper Generalized Decomposition-Based Framework
This paper presents a real-time global path planning method for mobile robots using harmonic functions, such as the Poisson equation, based on the Proper Generalized Decomposition (PGD) of these functions. The main property of the proposed technique is that the computational cost is negligible in real-time, even if the robot is disturbed or the goal is changed. The main idea of the method is the off-line generation, for a given environment, of the whole set of paths from any start and goal configurations of a mobile robot, namely the computational vademecum, derived from a harmonic potential field in order to use it on-line for decision-making purposes. Up until now, the resolution of the Laplace or Poisson equations has been based on traditional numerical techniques unfeasible for real-time calculation. This drawback has prevented the extensive use of harmonic functions in autonomous navigation, despite their powerful properties. The numerical technique that reverses this situation is the Proper Generalized Decomposition. To demonstrate and validate the properties of the PGD-vademecum in a potential-guided path planning framework, both real and simulated implementations have been developed. Simulated scenarios, such as an L-Shaped corridor and a benchmark bug trap, are used, and a real navigation of a LEGO®MINDSTORMS robot running in static environments with variable start and goal configurations is shown. This device has been selected due to its computational and memory-restricted capabilities, and it is a good example of how its properties could help the development of social robots
Direct measurement of stellar angular diameters by the VERITAS Cherenkov Telescopes
The angular size of a star is a critical factor in determining its basic
properties. Direct measurement of stellar angular diameters is difficult: at
interstellar distances stars are generally too small to resolve by any
individual imaging telescope. This fundamental limitation can be overcome by
studying the diffraction pattern in the shadow cast when an asteroid occults a
star, but only when the photometric uncertainty is smaller than the noise added
by atmospheric scintillation. Atmospheric Cherenkov telescopes used for
particle astrophysics observations have not generally been exploited for
optical astronomy due to the modest optical quality of the mirror surface.
However, their large mirror area makes them well suited for such
high-time-resolution precision photometry measurements. Here we report two
occultations of stars observed by the VERITAS Cherenkov telescopes with
millisecond sampling, from which we are able to provide a direct measurement of
the occulted stars' angular diameter at the milliarcsecond scale.
This is a resolution never achieved before with optical measurements and
represents an order of magnitude improvement over the equivalent lunar
occultation method. We compare the resulting stellar radius with empirically
derived estimates from temperature and brightness measurements, confirming the
latter can be biased for stars with ambiguous stellar classifications.Comment: Accepted for publication in Nature Astronom
Evidence for proton acceleration up to TeV energies based on VERITAS and Fermi-LAT observations of the Cas A SNR
We present a study of -ray emission from the core-collapse supernova
remnant Cas~A in the energy range from 0.1GeV to 10TeV. We used 65 hours of
VERITAS data to cover 200 GeV - 10 TeV, and 10.8 years of \textit{Fermi}-LAT
data to cover 0.1-500 GeV. The spectral analysis of \textit{Fermi}-LAT data
shows a significant spectral curvature around GeV that is
consistent with the expected spectrum from pion decay. Above this energy, the
joint spectrum from \textit{Fermi}-LAT and VERITAS deviates significantly from
a simple power-law, and is best described by a power-law with spectral index of
with a cut-off energy of TeV. These
results, along with radio, X-ray and -ray data, are interpreted in the
context of leptonic and hadronic models. Assuming a one-zone model, we exclude
a purely leptonic scenario and conclude that proton acceleration up to at least
6 TeV is required to explain the observed -ray spectrum. From modeling
of the entire multi-wavelength spectrum, a minimum magnetic field inside the
remnant of is deduced.Comment: 33 pages, 9 Figures, 6 Table
Total costs and benefits of biomass in selected regions of the European Union
The paper describes results of the BioCosts project in which a comprehensive analysis of the economic and environmental performance of the energy use of biomass was carried out for selected existing facilities throughout the European Union. It is demonstrated that the appropriately organized use of biofuels has significant environmental advantages compared to the use of fossil fuels. Mitigation of global warming is the largest single incentive to use biofuels. However, only a few technologies are economically competitive under prevailing conditions, while others lead to up to 100% higher energy production costs than fossil fuels. Employment effects of using biofuels are small but positive.http://www.sciencedirect.com/science/article/B6V2S-41JM99D-4/1/514a3253589af4590f84544e2966bcb
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