158 research outputs found
Adicción al deporte: el peligro de la sobredosis de ejercicio
La práctica deportiva forma parte del estilo de vida de los seres humanos postmodernos, pudiendo convertirse en una obsesión cuando su uso es excesivo, continuo, constante e intenso, pudiendo dar lugar a la adicción o dependencia al ejercicio. Actualmente son pocos los estudios e investigaciones hechos al respecto, por ello nuestro objetivo es analizar el estado de la cuestión, sus características psicológicas y psicopatológicas, y elaborar un cuestionario que permita evaluar la adicción al ejercicio, así como establecer su fiabilidad y validez para su detección y manejo clínico. Tras la elaboración del cuestionario, SAS, hemos pretendido observar cómo se manifiesta la adicción a nivel físico, psicológico y social. En este artículo presentamos los primeros resultados analizados tras un estudio exploratorio piloto a una muestra pequeña, N=33, compuesta por 16 mujeres y 17 hombres, que contestaron de forma voluntaria el cuestionario, compuesto por 40 ítems sencillos de respuesta dicotómica, (NO; SI). Aunque es una muestra limitada, la fiabilidad de dicho cuestionario es buena, con un Alpha de Cronbach superior a 0.8. Algunos de los enunciados del mismo han resultado ser muy específicos para la detección de la adicción, y asimismo, la edad y las horas dedicadas a la práctica de ejercicio físico tienen especial relevancia. Como conclusión se propone la primera escala española (SAS) para la detección de la adicción o dependencia al deporte, cuya fiabilidad y validez será analizada en estudios posteriores
Solar energetic electron events measured by MESSENGER and Solar Orbiter. Peak intensity and energy spectrum radial dependences: statistical analysis
Context/Aims: We present a list of 61 solar energetic electron (SEE) events
measured by the MESSENGER mission and the radial dependences of the electron
peak intensity and the peak-intensity energy spectrum. The analysis comprises
the period from 2010 to 2015, when MESSENGER heliocentric distance varied
between 0.31 and 0.47 au. We also show the radial dependencies for a shorter
list of 12 SEE events measured in February and March 2022 by spacecraft near 1
au and by Solar Orbiter around its first close perihelion at 0.32 au.
Results: Due to the elevated background intensity level of the particle
instrument on board MESSENGER, the SEE events measured by this mission are
necessarily large and intense; most of them accompanied by a CME-driven shock,
being widespread in heliolongitude, and displaying relativistic (1 MeV)
electron intensity enhancements. The two main conclusions derived from the
analysis of the large SEE events measured by MESSENGER, which are generally
supported by Solar Orbiter's data results, are: (1) There is a wide variability
in the radial dependence of the electron peak intensity between 0.3 au
and 1 au, but the peak intensities of the energetic electrons decrease
with radial distance from the Sun in 27 out of 28 events. On average and within
the uncertainties, we find a radial dependence consistent with . (2)
The electron spectral index found in the energy range around 200 keV
(200) of the backward-scattered population near 0.3 au measured by
MESSENGER is harder in 19 out of 20 (15 out of 18) events by a median factor of
20% (10%) when comparing to the anti-sunward propagating beam
(backward-scattered population) near 1 au.Comment: 20 pages, 13 figure
On the relevance of preprocessing in predictive maintenance for dynamic systems
The complexity involved in the process of real-time data-driven monitoring dynamic systems for predicted maintenance is usually huge. With more or less in-depth any data-driven approach is sensitive to data preprocessing, understood as any data treatment prior to the application of the monitoring model, being sometimes crucial for the final development of the employed monitoring technique. The aim of this work is to quantify the sensitiveness of data-driven predictive maintenance models in dynamic systems in an exhaustive way.
We consider a couple of predictive maintenance scenarios, each of them defined by some public available data. For each scenario, we consider its properties and apply several techniques for each of the successive preprocessing steps, e.g. data cleaning, missing values treatment, outlier detection, feature selection, or imbalance compensation. The pretreatment configurations, i.e. sequential combinations of techniques from different preprocessing steps, are considered together with different monitoring approaches, in order to determine the relevance of data preprocessing for predictive maintenance in dynamical systems
First near-relativistic solar electron events observed by EPD onboard Solar Orbiter
Context. Solar Orbiter, launched in February 2020, started its cruise phase in June 2020, in coincidence with its first perihelion at 0.51 au from the
Sun. The in situ instruments onboard, including the Energetic Particle Detector (EPD), operate continuously during the cruise phase enabling the
observation of solar energetic particles.
Aims. In situ measurements of the first near-relativistic solar electron events observed in July 2020 by EPD are analyzed and the solar origins and
the conditions for the interplanetary transport of these particles investigated.
Methods. Electron observations from keV energies to the near-relativistic range were combined with the detection of type III radio bursts and
extreme ultraviolet (EUV) observations from multiple spacecraft in order to identify the solar origin of the electron events. Electron anisotropies
and timing as well as the plasma and magnetic field environment were evaluated to characterize the interplanetary transport conditions.
Results. All electron events were clearly associated with type III radio bursts. EUV jets were also found in association with all of them except
one. A diversity of time profiles and pitch-angle distributions was observed. Different source locations and different magnetic connectivity and
transport conditions were likely involved. The July 11 event was also detected by Wind, separated 107 degrees in longitude from Solar Orbiter.
For the July 22 event, the Suprathermal Electron and Proton (STEP) sensor of EPD allowed for us to not only resolve multiple electron injections
at low energies, but it also provided an exceptionally high pitch-angle resolution of a very anisotropic beam. This, together with radio observations
of local Langmuir waves suggest a very good magnetic connection during the July 22 event. This scenario is challenged by a high-frequency
occultation of the type III radio burst and a nominally non-direct connection to the source; therefore, magnetic connectivity requires further
investigation
Light Perception in Two Strictly Subterranean Rodents: Life in the Dark or Blue?
BACKGROUND: The African mole-rats (Bathyergidae, Rodentia) are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. Because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. However, recent anatomical studies have suggested retention of basic visual capabilities. In this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they are able to discriminate colours and, finally, if the presence of light in burrows provokes plugging behaviour, which is assumed to have a primarily anti-predatory function. METHODOLOGY/PRINCIPAL FINDING: We used a binary choice test to show that the silvery mole-rat Heliophobius argenteocinereus and the giant mole-rat Fukomys mechowii exhibit a clear photoavoidance response to full-spectrum ("white"), blue and green-yellow light, but no significant reaction to ultraviolet or red light during nest building. The mole-rats thus retain dark/light discrimination capabilities and a capacity to perceive short to medium-wavelength light in the photopic range of intensities. These findings further suggest that the mole-rat S opsin has its absorption maximum in the violet/blue part of the spectrum. The assay did not yield conclusive evidence regarding colour discrimination. To test the putative role of vision in bathyergid anti-predatory behaviour, we examined the reaction of mole-rats to the incidence of light in an artificial burrow system. The presence of light in the burrow effectively induced plugging of the illuminated tunnel. CONCLUSION/SIGNIFICANCE: Our findings suggest that the photopic vision is conserved and that low acuity residual vision plays an important role in predator avoidance and tunnel maintenance in the African mole-rats
Comunicación entre el personal sanitario y el paciente afásico
Comunicación oral presentada en la Segunda Conferencia Internacional de Comunicación en Salud, celebrada el 23 de octubre de 2015 en la Universidad Carlos III de MadridIntroducción: la afasia es la pérdida de capacidad de expresión debida a una lesión temporal o crónica de los centros temporales. Se calcula que en España hay unos 300.000 casos. Las limitaciones varían dependiendo del área dañada, viéndose afectada su capacidad para hablar, leer, escribir o comprender. Objetivos: Conocer los principales errores
que comete el personal sanitario al comunicarse con el paciente afásico. Mostrar alternativas de comunicación entre paciente y personal sanitario. Fomentar la comunicación interprofesional. Metodología: se realiza una búsqueda bibliográfica en las bases de datos Dialnet, Lilacs, Medline y Cuiden Plus con las palabras “comunicación” “paciente” “afasia” para artículos a texto completo publicados en los últimos diez años. Resultados: la búsqueda ofreció resultados,
que después proceso de selección se redujeron a cuatro artículos. Resultados: la bibliografía sobre la temática
del estudio es escasa, la mayoría de los estudios se centran en el ámbito logopédico. Los profesionales que a diario se relacionan conel paciente afásico, carecen de formación en habilidades comunicativas, consecuencia de esro es que nos enfrentamos a una comunicación personal-paciente ineficaz reflejada en frustración en ambos. Se evidencia la necesidad de futuras líneas de investigación sobre este tema, con el fin, de mejorar la calidad de vida del enfermo afásico; así como
fomentar el dialogo entre logopedas y el resto de profesionales sanitarios
Unusually long path length for a nearly scatter-free solar particle event observed by Solar Orbiter at 0.43 au
Context: After their acceleration and release at the Sun, solar energetic particles (SEPs) are injected into the interplanetary medium and are bound to the interplanetary magnetic field (IMF) by the Lorentz force. The expansion of the IMF close to the Sun focuses the particle pitch-angle distribution, and scattering counteracts this focusing. Solar Orbiter observed an unusual solar particle event on 9 April 2022 when it was at 0.43 astronomical units (au) from the Sun.
//
Aims: We show that the inferred IMF along which the SEPs traveled was about three times longer than the nominal length of the Parker spiral and provide an explanation for this apparently long path.
//
Methods: We used velocity dispersion analysis (VDA) information to infer the spiral length along which the electrons and ions traveled and infer their solar release times and arrival direction.
//
Results: The path length inferred from VDA is approximately three times longer than the nominal Parker spiral. Nevertheless, the pitch-angle distribution of the particles of this event is highly anisotropic, and the electrons and ions appear to be streaming along the same IMF structures. The angular width of the streaming population is estimated to be approximately 30 degrees. The highly anisotropic ion beam was observed for more than 12 h. This may be due to the low level of fluctuations in the IMF, which in turn is very probably due to this event being inside an interplanetary coronal mass ejection The slow and small rotation in the IMF suggests a flux-rope structure. Small flux dropouts are associated with very small changes in pitch angle, which may be explained by different flux tubes connecting to different locations in the flare region.
//
Conclusions: The unusually long path length along which the electrons and ions have propagated virtually scatter-free together with the short-term flux dropouts offer excellent opportunities to study the transport of SEPs within interplanetary structures. The 9 April 2022 solar particle event offers an especially rich number of unique observations that can be used to limit SEP transport models
Isotopic Composition of Light Nuclei in Cosmic Rays: Results from AMS-01
The variety of isotopes in cosmic rays allows us to study different aspects
of the processes that cosmic rays undergo between the time they are produced
and the time of their arrival in the heliosphere. In this paper we present
measurements of the isotopic ratios 2H/4He, 3He/4He, 6Li/7Li, 7Be/(9Be+10Be)
and 10B/11B in the range 0.2-1.4 GeV of kinetic energy per nucleon. The
measurements are based on the data collected by the Alpha Magnetic
Spectrometer, AMS-01, during the STS-91 flight in 1998 June.Comment: To appear in ApJ. 12 pages, 11 figures, 6 table
- …