907 research outputs found

    Organización de un programa de implantes cocleares

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    A cochlear implant (CI) programme brings together a number of professionals who, during the stages of selection, surgery, programming, rehabilitation and monitoring, develop a series of tasks aimed at promoting comprehensive attention to the implanted patient. The aim of this paper was to describe in detail the tasks in each of the phases described in a programme of CI, materials and necessary equipment and the role of the professionals involved. It also raised a number of recommendations on how to develop a CI programme gradually to facilitate the progression from the simplest to the mos

    Comparing Poynting flux dominated magnetic tower jets with kinetic-energy dominated jets

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    Magnetic Towers represent one of two fundamental forms of MHD outflows. Driven by magnetic pressure gradients, these flows have been less well studied than magneto-centrifugally launched jets even though magnetic towers may well be as common. Here we present new results exploring the behavior and evolution of magnetic tower outflows and demonstrate their connection with pulsed power experimental studies and purely hydrodynamic jets which might represent the asymptotic propagation regimes of magneto-centrifugally launched jets. High-resolution AMR MHD simulations (using the AstroBEAR code) provide insights into the underlying physics of magnetic towers and help us constrain models of their propagation. Our simulations have been designed to explore the effects of thermal energy losses and rotation on both tower flows and their hydro counterparts. We find these parameters have significant effects on the stability of magnetic towers, but mild effects on the stability of hydro jets. Current-driven perturbations in the Poynting Flux Dominated (PDF) towers are shown to be amplified in both the cooling and rotating cases. Our studies of the long term evolution of the towers show that the formation of weakly magnetized central jets within the tower are broken up by these instabilities becoming a series of collimated clumps which magnetization properties vary over time. In addition to discussing these results in light of laboratory experiments, we address their relevance to astrophysical observations of young star jets and outflow from highly evolved solar type stars.Comment: 11 pages, 4 figures, accepted for publication in the High Energy Density Physics Journal corresponding to the proceedings of the 9th International Conference on High Energy Density Laboratory Astrophysics, May 4, 2012, Tallahassee Florid

    Tipos de implantes activos de oído medio

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    Active middle ear implants are classified as piezoelectric implants, which use the properties of piezoelectric materials. There are two types of piezoelectric implants: monomorphic and dimorphic; electromagnetic transduction uses a magnet, usually a rare earth magnet (e.g. samarium cobalt) and an energizing coil. This magnetic field causes the magnet to vibrate, which in turn, through the tympanic-ossicular chain, causes movement of the cochlear fluids. Electromechanical transduction is a variation of electromagnetic transduction

    On the structure and stability of magnetic tower jets

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    Modern theoretical models of astrophysical jets combine accretion, rotation, and magnetic fields to launch and collimate supersonic flows from a central source. Near the source, magnetic field strengths must be large enough to collimate the jet requiring that the Poynting flux exceeds the kinetic-energy flux. The extent to which the Poynting flux dominates kinetic energy flux at large distances from the engine distinguishes two classes of models. In magneto-centrifugal launch (MCL) models, magnetic fields dominate only at scales 100\lesssim 100 engine radii, after which the jets become hydrodynamically dominated (HD). By contrast, in Poynting flux dominated (PFD) magnetic tower models, the field dominates even out to much larger scales. To compare the large distance propagation differences of these two paradigms, we perform 3-D ideal MHD AMR simulations of both HD and PFD stellar jets formed via the same energy flux. We also compare how thermal energy losses and rotation of the jet base affects the stability in these jets. For the conditions described, we show that PFD and HD exhibit observationally distinguishable features: PFD jets are lighter, slower, and less stable than HD jets. Unlike HD jets, PFD jets develop current-driven instabilities that are exacerbated as cooling and rotation increase, resulting in jets that are clumpier than those in the HD limit. Our PFD jet simulations also resemble the magnetic towers that have been recently created in laboratory astrophysical jet experiments.Comment: 16 pages, 11 figures, published in ApJ: ApJ, 757, 6

    Aportaciones al conocimiento de la flora muscinal del Pirineo Occidental

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    In this paper we give citations of 122 taxa of mosses, which have been collected in 31 sites in the Western Pyrenees, in Navarra (Northern Spain). 9 of them are new records to the moss flora of Navarra and 2 are new records both for Navarra and for all the Pyrenees. Some of the more noticeable novelties are Dicranum crassifolium Sérgio, Ochyra & Séneca, Orthotrichum acuminatum H. Phillib. and Orthotrichum shawii Wilson

    The magnetized medium around the radio galaxy B2 0755+37: an interaction with the intra-group gas

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    We explore the magneto-ionic environment of the isolated radio galaxy B2 0755+37 using detailed imaging of the distributions of Faraday rotation and depolarization over the radio source from Very Large Array observations at 1385,1465 and 4860 MHz and new X-ray data from XMM-Newton. The Rotation Measure (RM) distribution is complex, with evidence for anisotropic fluctuations in two regions. The approaching lobe shows low and uniform RM in an unusual `stripe' along an extension of the jet axis and a linear gradient transverse to this axis over its Northern half. The leading edge of the receding lobe shows arc-like RM structures with sign reversals. Elsewhere, the RM structures are reasonably isotropic. The RM power spectra are well described by cut-off power laws with slopes ranging from 2.1 to 3.2 in different sub-regions. The corresponding magnetic-field autocorrelation lengths, where well-determined, range from 0.25 to 1.4 kpc. It is likely that the fluctuations are mostly produced by compressed gas and field around the leading edges of the lobes. We identify areas of high depolarization around the jets and inner lobes. These could be produced by dense gas immediately surrounding the radio emission containing a magnetic field which is tangled on small scales. We also identify four ways in which the well known depolarization (Faraday depth) asymmetry between jetted and counter-jetted lobes of extended radio sources can be modified by interactions with the surrounding medium.Comment: 16 pages, 13 figures, accepted for publication in MNRAS. Full resolution paper available at: ftp://ftp.ira.inaf.it/pub/outgoing/guidetti/ Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO

    Detección de personas en riesgo de padecer diabetes en farmacias comunitarias españolas

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    Objetivo: Detectar personas con riesgo alto/muy alto de padecer diabetes y derivarlas al médico, evaluar en la muestra la prevalencia de los distintos factores de riesgo y realizar una intervención educativa mínima sobre éstos en todos los usuarios participantes.Material y métodos: Estudio observacional transversal realizado en noviembre de 2014. Se incluyeron usuarios de la farmacia, mayores de 18 años, no diagnosticados de diabetes y que aceptaron realizar la encuesta. Muestreo no probabilístico.Variable principal: puntuación obtenida en el cuestionario Findrisc. Otras: características demográficas, IMC, perímetro de cintura, glucemia capilar (si F≥15), medicación, intervención, tiempo empleado.Resultados: Participaron 90 farmacéuticos de las 17 comunidades autónomas. Realizaron 1.520 cuestionarios Findrisc. La puntuación media de la muestra fue de 10,9 (DE=5,1). El número de individuos con riesgo alto o muy alto fue de 370 (24,3%) de los 1.520 encuestados. 207, el 55,9% de aquellos y el 13,6% de la muestra total, tenían glucemia ≥110 mg/dL y se derivaron al médico. Existe relación directa entre el número de medicamentos utilizados y el riesgo de diabetes. El tiempo empleado en la intervención fue de 9,9 (DE=5,1) minutos.Conclusiones: El alto porcentaje de participantes con riesgo alto/muy alto de padecer diabetes que son derivados al médico de familia para valorar su situación, avala la eficiencia de la farmacia en este tipo de cribados. La intervención educativa realizada con los participantes supone una llamada de atención sobre la importancia del estilo de vida saludable orientado a la prevención de las enfermedades metabólicas

    Revisión de los criterios audiométricos en el tratamiento de la hipoacusia neurosensorial mediante audífonos y prótesis auditivas implantables

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    Sensorineural hearing loss has a high incidence in our population; as a matter of fact, 50 % of people above 75 years of age suffer this impairment. Due to the advances in the devices to alleviate this condition and their verified efficacy, it is now appropriate to review the indications for these devices and provide a detailed description of the audioprosthetic systems used. These systems can be classified as external non-implantable devices (hearing aids) and implantable prostheses. The latter can be sub-divided into active implants in the external ear or middle ear, cochlear implants, and auditory brainstem implants (ABI). Indications for each group are determined by the type and location of the underlying condition as well as by the anatomic, functional, and social characteristics of each patient. It must be stressed that the selection and monitoring of the treatment is up to the specialist. Generally speaking, an attempt is made to facilitate the integration of the hypoacusic patients to their sound setting by enhancing their understanding of the spoken word and restoring binaurality, while at the same time, seeking to retain the plasticity of central auditory routes through the stimulation provided by any of these systems. In the course of this review, we refer to newly-emerging indications in both the field of cochlear implants (bimodal stimulation, implantation in patients with residual hearing, bilateral implants, etc) and in the area of ABI in patients with tumoural disease previously treated with radiosurgery or patients with non-tumour pathologies presenting malformations or bilateral cochlear ossification

    From Bipolar to Elliptical: Simulating the Morphological Evolution of Planetary Nebulae

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    The majority of Proto-planetary nebulae (PPN) are observed to have bipolar morphologies. The majority of mature PN are observed to have elliptical shapes. In this paper we address the evolution of PPN/PN morphologies attempting to understand if a transition from strongly bipolar to elliptical shape can be driven by changes in the parameters of the mass loss process. To this end we present 2.5D hydrodynamical simulations of mass loss at the end stages of stellar evolution for intermediate mass stars. We track changes in wind velocity, mass loss rate and mass loss geometry. In particular we focus on the transition from mass loss dominated by a short duration jet flow (driven during the PPN phase) to mass loss driven by a spherical fast wind (produced by the central star of the PN). We address how such changes in outflow characteristics can change the nebula from a bipolar to an elliptical morphology. Our results show that including a period of jet formation in the temporal sequence of PPN to PN produces realistic nebular synthetic emission geometries. More importantly such a sequence provides insight, in principle, into the apparent difference in morphology statistics characterizing PPN and PN systems. In particular we find that while jet driven PPN can be expected to be dominated by bipolar morphologies, systems that begin with a jet but are followed by a spherical fast wind will evolve into elliptical nebulae. Furthermore, we find that spherical nebulae are highly unlikely to ever derive from either bipolar PPN or elliptical PN.Comment: Accepted for publication in the MNRAS, 15 pages, 7 figure

    The immunotherapy potential of agonistic anti-CD137 (4-1BB) monoclonal antibodies for malignancies and chronic viral diseases

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    Pharmacological intervention on the immune system to achieve more intense lymphocyte responses has potential application in tumour immunology and in the treatment of chronic viral diseases. Immunostimulating monoclonal antibodies are defined as a new family of drugs that augment cellular immune responses. They interact as artificial ligands with functional proteins of the immune system, either activating or inhibiting their functions. There are humanized monoclonal antibodies directed to the inhibitory receptor CD152 (CTLA-4) that are being tested in clinical trials with evidence of antitumoural activity. As a drawback, anti-CTLA-4 monoclonal antibodies induce severe autoimmunity reactions in a fraction of the patients. Anti-CD137 monoclonal antibodies have the ability to induce potent immune responses mainly mediated by cytotoxic lymphocytes with the result of frequent complete tumour eradications in mice. Comparative studies in experimental models indicate that the antitumour activity of anti-CD137 monoclonal antibodies is superior to that of anti-CD152. CD137 (4-1BB) is a leukocyte differentiation antigen selectively expressed on the surface of activated T and NK lymphocytes, as well as on dendritic cells. Monoclonal antibodies acting as artificial stimulatory ligands of this receptor (anti-CD137 agonist antibodies) enhance cellular antitumoural and antiviral immunity in a variety of mouse models. Paradoxically, anti-CD137 monoclonal antibodies are therapeutic or preventive in the course of model autoimmune diseases in mice. In light of these experimental results, a number of research groups have humanized antibodies against human CD137 and early clinical trials are about to start
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