4,705 research outputs found
The Ljapunov-Schmidt reduction for some critical problems
This is a survey about the application of the Ljapunov-Schmidt reduction for
some critical problems
A magnetic reconnection model for explaining the multi-wavelength emission of the microquasars Cyg X-1 and Cyg X-3
Recent studies have indicated that cosmic ray acceleration by a first-order
Fermi process in magnetic reconnection current sheets can be efficient enough
in the surrounds of compact sources. In this work, we discuss this acceleration
mechanism operating in the core region of galactic black hole binaries (or
microquasars) and show the conditions under which this can be more efficient
than shock acceleration. In addition, we compare the corresponding acceleration
rate with the relevant radiative loss rates obtaining the possible energy
cut-off of the accelerated particles and also compute the expected spectral
energy distribution (SED) for two sources of this class, namely Cygnus X-1 and
Cygnus X-3, considering both leptonic and hadronic processes. The derived SEDs
are comparable to the observed ones in the low and high energy ranges. Our
results suggest that hadronic non-thermal emission due to photo-meson
production may produce the very high energy gamma-rays in these microquasars.Comment: 17 pages and 7 figures. Accepted for publication in the Monthly
Notices of the Royal Astronomical Society (MNRAS
¡Los miuras! : sainete lÃrico-taurino en un acto y en prosa
Estrenado en el Teatro del Duque, de Sevilla, el 27 de enero de 1909Copia digital. Valladolid : Junta de Castilla y León. ConsejerÃa de Cultura y Turismo, 201
Mes de abril consagrado á San Juan Evangelista
Precede a la mención de responsabilidad una cruz latinaCopia digital. Valladolid : Junta de Castilla y León. ConsejerÃa de Cultura y Turismo, 2010-201
Varied nanostructures from a single multifunctional molecular material
The control of the morphology of nanostructures formed from a single component molecular material incorporating electron accepting and donating moieties is shown, from both solution and gel states. The compound comprises one tetrathiafulvalene (TTF) and two pyrene units which act as the [small pi]-electron rich and deficient units, respectively, and which are united by amide-containing linkers whose additional role is to aide aggregation by hydrogen bonding. This role was demonstrated by IR and NMR spectroscopy. The gels were deposited onto surfaces and the solvent allowed to evaporate, leaving films formed by meshes of fibres with different morphologies in accord with the different solvents used to form the materials. Doping of these xerogels with iodine vapour afforded conducting films whose characteristics were probed with current sensing atomic force microscopy (CS-AFM), providing current maps and I-V curves which show how dramatically the processing solvent can influence the electronic properties of these xerogel-derived materials
Modulación de la elongación axonal y la excitabilidad neuronal por receptores purinérgicos P2Y1, P2Y13 y P2X7
Tesis doctoral inédita leÃda en la Universidad Autónoma de Madrid. Facultad de Ciencias, Departamento de BiologÃa Molecular. Fecha de lectura: 06-09-201
Adventures of a tidally induced bar
Using N-body simulations, we study the properties of a bar induced in a discy dwarf galaxy as a result of tidal interaction with the Milky Way. The bar forms at the first pericentre passage and survives until the end of the evolution at 10 Gyr. Fourier decomposition of the bar reveals that only even modes are significant and preserve a hierarchy so that the bar mode is always the strongest. They show a characteristic profile with a maximum, similar to simulated bars forming in isolated galaxies and observed bars in real galaxies. We adopt the maximum of the bar mode as a measure of the bar strength and we estimate the bar length by comparing the density profiles along the bar and perpendicular to it. The bar strength and the bar length decrease with time, mainly at pericentres, as a result of tidal torques acting at those times and not to secular evolution. The pattern speed of the bar varies significantly on a time-scale of 1 Gyr and is controlled by the orientation of the tidal torque from the Milky Way. The bar is never tidally locked, but we discover a hint of a 5/2 orbital resonance between the third and fourth pericentre passage. The speed of the bar decreases in the long run so that the bar changes from initially rather fast to slow in the later stages. The boxy/peanut shape is present for some time and its occurrence is preceded by a short period of buckling instability
Plan PrEFiNE: Plan estratégico para la enfermedad de Fabry en NefrologÃa
Background Renal failure is one of the main causes of death in patients with Fabry disease (FD). Due to the low prevalence of FD, delayed diagnosis and misdiagnosis, often the correct diagnosis is made when organ damage is already present. Early recognition of the disease would allow the prevention of severe complications and the premature death of patients with FD. Objective We present here the PrEFiNE project, which includes a wide spectrum of activities with the aim of improve knowledge and diagnosis of FD. The project is sponsored by Shire Iberia (http://shireiberica.com/) Methods From January 2016 to the end of 2017 several activities will be carried out, starting with a survey to evaluate current FD knowledge among nephrologists; in addition some studies to assess prevalence of this disease will be performed. One study will include patients receiving dialysis, another study will cover kidney transplant patients, and a pilot study in chronic kidney disease in stage 3-5 predialysis. Also planned is a pharmacoeconomic study to focus on burden of FD. At the same time medical education activities will be conducted both on line and on site. Plan for dissemination will include medical publications and diffusion to media. PrEFiNE Project will finish with the publication of a compilation book on FD in Nephrology including all planned activities and proposing recommendations based on results and detected unmet needs. PrEfiNE Plan will be coordinated by severa scientific committees, one at national level and 10 other regionals comittees, tha will be responsible to ensure the maximum scientific quality of proposed activities. An advisory board will supervise the project. Discussion PrEfiNE project will evaluate an action plan focused on improving FD knowledge to make necessary recommendations for an early recognition of the disease. In addition will generate a plan to improve previously undetected needs.Justificación: La enfermedad renal es una de las principales causas de muerte entre los
pacientes con enfermedad de Fabry (EF). Al tratarse de una enfermedad de baja prevalencia,
se realizan con frecuencia diagnósticos erróneos y retrasados, que a menudo se dan cuando
ya se ha producido danËœ o orgánico. El reconocimiento temprano de la enfermedad permitirÃa
evitar las complicaciones graves y la muerte prematura en estos pacientes.
Objetivo: Presentamos en este artÃculo un resumen del plan PrEFiNE, que incluye un abanico
amplio de actividades con el objetivo de mejorar el conocimiento y reconocimiento de la EF
entre los nefrólogos.
Este proyecto está patrocinado por Shire Ibérica (http://shireiberica.com/).
Métodos: Desde enero de 2016 y hasta finales del 2017 se iniciarán distintas actividades,
comenzando por una evaluación del grado de conocimiento que existe actualmente sobre
la EF. Se incluyen 3 estudios de prevalencia de la EF, que abarcan el espectro de los pacientes
con enfermedad renal crónica (pacientes en diálisis, pacientes trasplantados renales y un
estudio piloto en pacientes con enfermedad renal crónica en estadio 3–5 prediálisis) y un
estudio farmacoeconómico, centrado en el impacto de la carga de la enfermedad. Parale-
lamente, se realizarán actividades formativas tanto presenciales como on line, y un amplio
plan de comunicación mediante publicaciones y difusión a medios. El proyecto culminará
con la publicación de un libro blanco de la EF en NefrologÃa, que recoja el resultado de
todas las actividades y que proponga recomendaciones en respuesta a los resultados y a las
necesidades detectadas.
El plan PrEFiNE estará coordinado por distintos comités cientÃficos, uno nacional y 10
regionales que garantizarán el desarrollo de las acciones con el máximo rigor cientÃfico
y será supervisado por un comité asesor.
Discusión: El plan PrEFiNE nos permitirá evaluar la utilidad de un proyecto dirigido a mejorar
el conocimiento de una enfermedad minoritaria como la EF a nivel nacional, y a partir del
cual se podrán establecer las recomendaciones necesarias para mejorar su reconocimiento,
además de planes enfocados a mejorar las necesidades no cubiertas detectadas durante su
desarroll
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