907 research outputs found
Organización de un programa de implantes cocleares
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
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
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
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 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
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
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
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
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
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
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
- …
