2,957 research outputs found
Realidades alternativas como soporte para el desarrollo sostenible
En los últimos tiempos el término Desarrollo Sostenible ha cobrado fuerza. Su objetivo hace referencia a responder a las necesidades del presente de forma igualitaria, sin comprometer las posibilidades de sobrevivencia y prosperidad de las generaciones futuras. Esto lleva a la sociedad actual a enfrentar sus problemas operando de un modo ecológicamente sustentable e intentando mejorar la calidad vida de la mayor cantidad de personas.
Por otro lado, la tecnología ha tenido un crecimiento exponencial que ha impactado en todos los ámbitos de nuestra vida cotidiana. En él se encuentran las tecnologías de Realidad Virtual y Realidad Aumentada, que gracias a su versatilidad y amplitud de posibilidad de aplicación, han logrado captar el interés de diversas áreas del conocimiento. Su transversalidad las convierte en posibles generadoras de iniciativas sostenibles que impactan en la educación, la concientización, el entrenamiento en cualquier ámbito, y muy específicamente en la salud, donde tienen un uso primordial.
Esta propuesta de trabajo expone sobre el potencial de la Realidad Virtual y Realidad Aumentada en el alcance de los Objetivos de Desarrollo Sostenible propuestos por Naciones Unidas, con el fin de satisfacer las necesidades actuales sin comprometer los recursos y posibilidades de las futuras generaciones.Eje: Computación Gráfica, Imágenes y Visualización.Red de Universidades con Carreras en Informátic
Spin-orbit torque from the introduction of Cu interlayers in Pt/Cu/Co/Pt nanolayered structures for spintronic devices
Spin currents can modify the magnetic state of ferromagnetic ultrathin films through spin-orbit torque. They may be generated by means of spin-orbit interactions by either bulk or interfacial phenomena. Electrical transport measurements reveal a 6-fold increase of the spin-orbit torque accompanied by a drastic reduction of the spin Hall magnetoresistance upon the introduction of an ultrathin Cu interlayer in a Pt/Cu/Co/Pt structure with perpendicular magnetic anisotropy. We analyze the dependence of the spin Hall magnetoresistance with the thickness of the interlayer, ranging from 0.5 to 15 nm, in the frame of a drift diffusion model that provides information on the expected spin currents and spin accumulations in the system. The results demonstrate that the major responsibility of both effects is spin memory loss at the interface. The enhancement of the spin-orbit torque when introducing an interlayer opens the possibility to design more efficient spintronic devices based on materials that are cheap and abundant such as copper. More specifically, spin-orbit torque magnetic random access memories and spin logic devices could benefit from the spin-orbit torque enhancement and cheaper material usage presented in this study
The electrical double layer for a fully asymmetric electrolyte around a spherical colloid: an integral equation study
The hypernetted chain/mean spherical approximation (HNC/MSA) integral
equation is obtained and solved numerically for a totally asymmetric primitive
model electrolyte around a spherical macroparticle. The ensuing radial
distribution functions show a very good agreement when compared to our Monte
Carlo and molecular dynamics simulations for spherical geometry and with
respect to previous anisotropic reference HNC calculations in the planar limit.
We report an analysis of the potential vs charge relationship, radial
distribution functions, mean electrostatic potential and cumulative reduced
charge for representative cases of 1:1 and 2:2 salts with a size asymmetry
ratio of 2. Our results are collated with those of the Modified Gouy-Chapman
(MGC) and unequal radius Modified Gouy-Chapman (URMGC) theories and with those
of HNC/MSA in the restricted primitive model (RPM) to assess the importance of
size asymmetry effects. One of the most striking characteristics found is
that,\textit{contrary to the general belief}, away from the point of zero
charge the properties of an asymmetric electrical double layer (EDL) are not
those corresponding to a symmetric electrolyte with the size and charge of the
counterion, i.e. \textit{counterions do not always dominate}. This behavior
suggests the existence of a new phenomenology in the EDL that genuinely belongs
to a more realistic size-asymmetric model where steric correlations are taken
into account consistently. Such novel features can not be described by
traditional mean field theories like MGC, URMGC or even by enhanced formalisms,
like HNC/MSA, if they are based on the RPM.Comment: 29 pages, 13 figure
Noble gas variation during partial crustal melting and magma ascent processes
Noble gas isotopes, although present in trace amounts, are generally more reliable and less ambiguous recorders of their source than the major volatile species. In volcanic settings in particular, this advantage derives from their chemical inertness, as noble gas isotopic and elemental fractionations are strongly coupled to their source and modified only by physical processes during magma ascent and eruption. The Neogene volcano El Hoyazo (Betic Cordillera, SE Spain) is a highly favourable natural laboratory to study the links between partial crustal melting processes occurring at depth and the eruptive products at the surface, because partially melted crustal xenoliths are preserved in silicic lavas. Comparing the noble gas isotopic compositions of xenoliths and lavas has the potential to yield new insights into volatile behaviour during melting processes at inaccessible depths in the crust.
At El Hoyazo, noble gases trapped in lava glasses, and the fluid/melt inclusions within xeno- and phenocrysts, provide novel information on: (i) their response to the crustal melting process including mechanisms such as magma mixing (and crustal assimilation) of two endmembers: i.e. the extracted felsic melt from the country metapelitic crust, and the basic-intermediate magma from the underplating in the region. The results reveal significant modification of magmatic noble gases by the interaction with the partially melted crust; (ii) noble gas variations during degassing and magma ascent, showing higher atmospheric influence in the lava samples from shallower depths than in the deeper lavas and minerals; and (iii) higher magmatic influence in crystals of garnet from deeper lava than in both shallower crystals of amphibole, and garnet crystals within the crustal xenoliths. In addition, we find that noble gases in melt inclusions are also likely accumulating in their shrinkage bubbles, and not only remaining dissolved in the melt.Postprint3,51
Influencing Factors in Autotransplantation of Teeth with Open Apex: A Review of the Literature
Dental autotransplantation is the process by which a tooth located in its natural socket is extracted and relocated to another socket in which the tooth is missing or has been extracted due to various reasons such as trauma, extensive caries or periapical pathology, among other reasons. This proposed technique offers a more conservative alternative for patients in comparison with prosthetic or implant techniques, especially in young patients where implants are contraindicated until their maxillary bone system’s growth ends. Thus, the objective of this review was to present a qualitative synthesis of the risk factors that influence the results of open apex dental autotransplantation in humans. After confirming that there are various factors that influence dental autotransplantation, it was concluded that the extra-alveolar time of the donor tooth and the periodontal damage of the root of the donor tooth are the factors of greatest interest in the literature, both closely linked to the use of 3D replication of the transplanted toot
3D numerical model of the Omega Nebula (M17): simulated thermal X-ray emission
We present 3D hydrodynamical simulations of the superbubble M17, also known
as the Omega nebula, carried out with the adaptive grid code yguazu'-a, which
includes radiative cooling. The superbubble is modelled considering the winds
of 11 individual stars from the open cluster inside the nebula (NGC 6618), for
which there are estimates of the mass loss rates and terminal velocities based
on their spectral types. These stars are located inside a dense interstellar
medium, and they are bounded by two dense molecular clouds.
We carried out three numerical models of this scenario, considering different
line of sight positions of the stars (the position in the plane of the sky is
known, thus fixed). Synthetic thermal X-ray emission maps are calculated from
the numerical models and compared with ROSAT observations of this astrophysical
object. Our models reproduce successfully both the observed X-ray morphology
and the total X-ray luminosity, without taking into account thermal conduction
effects.Comment: 8 pages, 6 figures, accepted for publication in MNRA
Photoluminescence of monocrystalline and stain-etched porous silicon doped with high temperature annealed europium
New developments in Micromegas Microbulk detectors
A new Micromegas manufacturing technique, based on kapton etching technology,
has been recently developed, improving the uniformity and stability of this
kind of readouts. Excellent energy resolutions have been obtained, reaching 11%
FWHM for the 5.9 keV photon peak of 55Fe source and 1.8% FWHM for the 5.5 MeV
alpha peak of the 241Am source. The new detector has other advantages like its
flexible structure, low material and high radio-purity. The two actual
approaches of this technique will be described and the features of these
readouts in argon-isobutane mixtures will be presented. Moreover, the low
material present in the amplification gap makes these detectors approximate the
Rose and Korff model for the avalanche amplification, which will be discussed
for the same type of mixtures. Finally, we will present several applications of
the microbulk technique.Comment: To be published in the Proceedings of the TIPP2011 conference
(Physics Procedia
Contribution of EARLINET/ACTRIS to the summer 2013 Special Observing Period of the ChArMEx project: monitoring of a Saharan dust event over the western and central Mediterranean
In the framework of the Chemistry-Aerosol Mediterranean
Experiment (ChArMEx; http://charmex.lsce.ipsl.fr/) initiative, a
field campaign took place in the western Mediterranean Basin
between 10 June and 5 July 2013 within the ADRIMED (Aerosol
Direct Radiative Impact on the regional climate in the
MEDiterranean region) project. The scientific objectives of
ADRIMED are the characterization of the most common
‘Mediterranean aerosols’ and their direct radiative forcing (column
closure and regional scale). During 15–24 June a multiintrusion
dust event took place over the western and central
Mediterranean Basin. Extra measurements were carried out by
some EARLINET/ACTRIS (European Aerosol Research Lidar
Network /Aerosols, Clouds, and Trace gases Research
InfraStructure Network, http://www.actris.net/) lidar stations in
Spain and Italy, in particular on 22 June in support to the flight
over southern Italy of the Falcon 20 aircraft involved in the
campaign. This article describes the physical and optical properties
of dust observed at the different lidar stations in terms ofdust plume centre of mass, optical depth, lidar ratio, and particle
depolarization ratio. To link the differences found in the
origin of dust plumes, the results are discussed on the basis
of back-trajectories and air- and space-borne lidars. This work
puts forward the collaboration between a European research
infrastructure (ACTRIS) and an international project (ChArMEx)
on topics of interest for both parties, and more generally for the
atmospheric community.Published4698-47114A. Clima e OceaniJCR Journalrestricte
ACE and CXCL10 as predictive biomarkers in the LEA study
Background: LEA Study (GEICAM/2006-11/GBG51), is a randomized clinical trial comparing bevacizumab in combination with endocrine therapy (ET + B) with endocrine therapy (ET) in postmenopausal women with advanced or metastatic HR-positive/HER2-negative breast cancer (BC) with indication of hormonotherapy as first-line treatment. Patients with secondary hypertension had better progression-free survival (PFS) and overall survival (OS). We have evaluated the role of two hypertension-related biomarkers, Angiotensin-Converting Enzyme (ACE) and Small-Inducible Cytokine B10 (CXCL10) as prognostic and/or predictive biomarkers of benefit to bevacizumab in the first line metastatic disease.
Methods: From 380 patients, 266 were included in 33 Spanish sites. Median age was 64 years, 63.5% had measurable disease, 97.4% were metastatic at randomization, 51.5% had visceral disease and 52.6% received previous chemotherapy. PFS was 14.3 months (range 0.8-61.1), OS was 34 months (range 0.8-71.6) and 93 patients had Objective Response (OR). We analyzed 124 plasma samples collected before treatment (52 from ET and 72 from ET + B arms). Circulating levels of ACE and CXCL10 were determined by ELISA. ACE levels of 115ng/ml and 135ng/ml were pre-defined as cutoff values. CXCL10 was explored as a quantitative variable.
Results: PFS was 15.1 months (range 1.4-61.1), OS was 31.1 months (range 2.8-61.1) and 40.3% had OR. OR was significantly different between treatment arms (p < 0.001) but not PFS or OS. Median ACE concentration was 130.9ng/ml (range 35.3-315.4). Low ACE (<135ng/ml) had better PFS in the whole population (p = 0.048) and in the ET + B arm (p = 0.041). ACE cutoff of 115 ng/ml was not able to identify any subgroup with better prognosis. Median CXCL10 concentration was 230.3pg/ml (range 15.1-4129.6). A higher expression of CXCL10 was significantly associated with worse OS in the whole population (p < 0.0001) and each treatment arm (p = 0.002 and p = 0.001 in ET and ET + B, respectively). No association with OR were identified neither for ACE nor for CXCL10.
Conclusions: ACE levels could be considered a prognostic and a bevacizumab predictive biomarker of PFS. CXCL10 could be prognostic of OS. Confirmatory studies are warranted
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