2,223 research outputs found
Enfermedad de Alzheimer y pérdida auditiva
Despite the different epidemiological, neurophysiological and
morphological studies published in the literature, it is still not known for sure
whether there is a relation between Alzheimer's disease (AD) and peripheral
hearing loss. In this work we conduct an auditory study in patients with AD and
in volunteer controls in order to investigate this possible relationship.
SUBJECTS AND METHODS: The sample studied consisted of 14 patients with a clinical
diagnosis of probable AD (age: 79 Y 6 years) and 14 volunteers (age: 76 Y 5
years) who visited the Clinica Universidad de Navarra. After applying a set of
thorough criteria to preclude any previous hearing problems, all the participants
underwent a subjective hearing assessment by means of pure-tone threshold
audiometry and vocal audiometry and an objective auditory assessment using a
tympanometry study, stapedial reflex, otoacoustic emissions and brainstem
auditory evoked potentials. For the analysis, patients with AD and controls were
paired homogenously by sex and age. RESULTS: The main obstacle hindering the
study was to recruit the participants, due to the fact that they did not see any
direct benefit from the study and it demanded an excessive amount of their time.
Pure-tone threshold audiometry showed that patients with AD had a pattern of
greater hearing loss for acute frequencies, with statistically significant
differences. No significant differences were found in the analysis of the rest of
the subjective and objective hearing tests. CONCLUSIONS: The findings of our
study both agree and disagree with some earlier works from the literature, which
suggests that patients with AD may have their own auditory patter
Second-order semi-implicit projection methods for micromagnetics simulations
Micromagnetics simulations require accurate approximation of the magnetiza- tion dynamics described by the Landau-Lifshitz-Gilbert equation, which is non- linear, nonlocal, and has a non-convex constraint, posing interesting challenges in developing numerical methods. In this paper, we propose two second-order semi-implicit projection methods based on the second-order backward differen- tiation formula and the second-order interpolation formula using the informa- tion at previous two temporal steps. Unconditional unique solvability of both methods is proved, with their second-order accuracy verified through numerical examples in both 1D and 3D. The efficiency of both methods is compared to that of another two popular methods. In addition, we test the robustness of both methods for the first benchmark problem with a ferromagnetic thin film material from National Institute of Standards and Technology
Modulating the phase transition temperature of giant magnetocaloric thin films by ion irradiation
Magnetic refrigeration based on the magnetocaloric effect at room temperature
is one of the most attractive alternative to the current gas
compression/expansion method routinely employed. Nevertheless, in giant
magnetocaloric materials, optimal refrigeration is restricted to the narrow
temperature window of the phase transition (Tc). In this work, we present the
possibility of varying this transition temperature into a same giant
magnetocaloric material by ion irradiation. We demonstrate that the transition
temperature of iron rhodium thin films can be tuned by the bombardment of ions
of Ne 5+ with varying fluences up to 10 14 ions cm --2 , leading to optimal
refrigeration over a large 270--380 K temperature window. The Tc modification
is found to be due to the ion-induced disorder and to the density of new
point-like defects. The variation of the phase transition temperature with the
number of incident ions opens new perspectives in the conception of devices
using giant magnetocaloric materials
Quality classification of Spanish olive oils by untargeted gas chromatography coupled to hybrid quadrupole–time of flight mass spectrometry with atmospheric pressure chemical ionization and metabolomics-based statistical approach
The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including extra virgin, virgin and lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70 % taking the official established method, “PANEL TEST” as reference.The authors acknowledge the financial support of Generalitat Valenciana, as research group of excellence (PROMETEO II/2014/023) and Collaborative Research on Environment and Food-Safety (ISIC/2012/016). This work and C. Sales grant has been supported by Universitat Jaume I research promotion plans (P1-1B2013-70
An annotated and updated checklist of the ophsthobranchs ((Mollusca: Gastropoda) from Spain and Portugal (including islands and archipelagos)
The present publication is a new annotated and updated checklist of the opisthobranchs (Mollusca, Gastropoda) from the Spanish and Portuguese coasts, including their Atlantic archipelagos (Azores, Madeira, Selvagens and Canary Islands). The bathyal species recorded from the continental shelf of all these areas are also included. Incorporating a review of the literature, 523 species are included on the present checklist, 23 belonging to Architectibranchia, 111 to Cephalaspidea s. s., 14 to Anaspidea, 4 to Acochlidiomorpha, 37 to Thecosomata, 7 to Gymnosomata, 43 to Sacoglossa, 3 to Umbraculoidea, 16 to Pleurobranchoidea and 265 to Nudibranchia: 127 Doridoidea, 42 Dendronotoidea, 9 Arminoidea, and 87 Aeolidoidea. The records these species have been divided into 12 geographic sectors: 1) Spanish coast on the Bay of Biscay; 2) Galicia; 3) mainland coast of Portugal; 4) Andalusian Atlantic coast; 5) Straits of Gibraltar, including Ceuta (northern Africa); 6) Andalusian Mediterranean coast, ..
OxidaciĂłn a 1123 K de sistemas multicapa AISI 304-Ni/Al-Al2O3/TiO2 depositados mediante proyecciĂłn por llama
The oxidation behaviour of alumina/titania (97/3, 87/13 and 60/40) ceramic coatings using a Ni-Al coupling layer was studied in a thermobalance. Both layers were deposited on an AISI 304 stainless steel base metal by the flame spray technique. The coated steel was heated from room temperature to 1,123 K at 40 K min–1, oxidized in air for 50 h, and then cooled to room temperature at 40 K min–1. The mass gain was mainly attributed to the oxidation of Ni-Al coupling layer. Kinetic laws, DW·S–1 (mg.mm–2) vs. time (hours) were close to a parabolic plot for each sample. Surface composition of ceramic top layer and the cross section of multilayer system were analysed using a wide range of experimental techniques including Scanning Electron Microscopy (SEM), equipped with a link energy dispersive X-Ray spectroscopy (EDX) and X-Ray diffraction (XRD) before and after the oxidation process. Coatings 97/3 and 87/13 presented a stable structure after flame spray deposition and they did not evolve with the oxidation process, while most of the 60/40 coating changed to a metastable structure after deposition and to a more stable structure after oxidation with high micro-cracks content. SEM and EDX microanalysis of the cross-sections showed that significant oxidation and a weak intergranular precipitation had been produced in the coupling layer and on the stainless steel base metal, respectively.El comportamiento a oxidaciĂłn de recubrimientos cerámicos alĂşmina/titania (97/3, 87/13, 60/40) usando una capa de anclaje Ni-Al se ha estudiado mediante una termobalanza. Ambas capas se han depositado sobre un acero inoxidable AISI 304 utilizando la tĂ©cnica de proyecciĂłn llama (FS). El acero recubierto se ha calentado desde la temperatura ambiente hasta 1.123 K a 40 K min–1, se ha oxidado al aire durante 50 h, y luego se ha enfriado hasta la temperatura ambiente a 40 K min–1. La ganancia en masa se atribuye a la oxidaciĂłn de la capa de enganche Ni-Al. La cinĂ©tica DW·S–1 (mg.mm–2) vs. tiempo (horas) se ha ajustado a una ley parabĂłlica para todas las muestras. La composiciĂłn super- ficial de la capa cerámica y la secciĂłn transversal del sistema multicapa se han analizado mediante las tĂ©cnicas de MicroscopĂa ElectrĂłnica de Barrido (SEM), Espectroscopia de EnergĂas Dispersivas de Rayos X (EDX), DifracciĂłn de Rayos X (XRD) antes y despuĂ©s del proceso de oxidaciĂłn. Los recubrimientos 97/3 y 87/13 han presentado una estruc- tura estable tras el proceso de deposiciĂłn por proyecciĂłn por llama y esta estructura tampoco ha evolucionado despuĂ©s de la oxidaciĂłn, mientras la mayor parte del recubrimiento 60/40 ha cambiado a una estructura metaestable despuĂ©s la deposiciĂłn y finalmente ha evolucionado a una estructura más estable despuĂ©s de la oxidaciĂłn con alto contenido de microagrietamiento. El microanálisis mediante SEM y EDX de las secciones transversales han mostrado una oxidaciĂłn significativa en la capa de enganche y una dĂ©bil precipitaciĂłn intergranular en el material base AISI 30
On the true optical properties of zinc nitride
Copyright (2011) American Institute of Physics. The following article appeared in Applied Physics Letters 99.23 (2011): 232112-3 and may be found at http://apl.aip.org
Breaking Eight-fold Degeneracies in Neutrino CP Violation, Mixing, and Mass Hierarchy
We identify three independent two-fold parameter degeneracies (\delta,
\theta_{13}), sgn(\delta m^2_{31}) and (\theta_{23}, \pi/2-\theta_{23})
inherent in the usual three-neutrino analysis of long-baseline neutrino
experiments, which can lead to as much as an eight-fold degeneracy in the
determination of the oscillation parameters. We discuss the implications these
degeneracies have for detecting CP violation and present criteria for breaking
them. A superbeam facility with a baseline at least as long as the distance
between Fermilab and Homestake (1290 km) and a narrow band beam with energy
tuned so that the measurements are performed at the first oscillation peak can
resolve all the ambiguities other than the (\theta_{23}, \pi/2-\theta_{23})
ambiguity (which can be resolved at a neutrino factory) and a residual (\delta,
\pi-\delta) ambiguity. However, whether or not CP violation occurs in the
neutrino sector can be ascertained independently of the latter two ambiguities.
The (\delta,\pi-\delta) ambiguity can be eliminated by performing a second
measurement to which only the \cos\delta terms contribute. The hierarchy of
mass eigenstates can be determined at other oscillation peaks only in the most
optimistic conditions, making it necessary to use the first oscillation
maximum. We show that the degeneracies may severely compromise the ability of
the proposed SuperJHF-HyperKamiokande experiment to establish CP violation. In
our calculations we use approximate analytic expressions for oscillation
probabilitites that agree with numerical solutions with a realistic Earth
density profile.Comment: Revtex (singlespaced), 35 pages, 15 postscript figures, uses
psfig.st
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