547 research outputs found
Riemann Surfaces of genus g with an automorphism of order p prime and p>g
The present work completes the classification of the compact Riemann surfaces
of genus g with an analytic automorphism of order p (prime number) and p > g.
More precisely, we construct a parameteriza- tion space for them, we compute
their groups of uniformization and we compute their full automorphism groups.
Also, we give affine equations for special cases and some implications on the
components of the singular locus of the moduli space of smooth curves of genus
g.Comment: 28 pages, 5 figure
Loosy: un sintetizador digital en realidad mixta
Las aplicaciones musicales en realidad mixta tienen todavía un largo camino que recorrer, en parte debido a las limitaciones tecnológicas que imposibilitan una medición precisa de la posición de las manos, junto con la ausencia de un cuerpos físicos palpables que sirvan de apoyo y referencia para los hologramas. Loosy, el proyecto planteado en este trabajo, pretende resolver estos problemas mediante una interfaz que permite interpretar melodías con la mano derecha sin referencia visual o táctil al hacerlo de forma contínua en vez de discreta. La mano izquierda controla la armonía, que se elige pulsando sobre un panel virtual de grandes botones que el usuario puede agarrar y pegar a un objeto físico como una mesa o una pared, ofreciendo una referencia táctil para los cambios de armonía. A pesar de no haberse podido probar en un dispositivo de realidad aumentada y de haberse desarrollado sólo la funcionalidad básica, Loosy ya se presenta como una aplicación divertida e intuitiva, incluso para alguien sin conocimientos musicales, y se espera completar su desarrollo para explotarla comercialmente en un futuro próximo
Compartir, conviure i comprendre. Viatge a través de les nostres vivències
S’exposen les metodologies i objectius d’un recull d’experiències educatives que ajuden als
infants a comprendre el món mitjançant l’ús d’eines i recursos culturals matemàtics. Aquestes
experiències s’han realitzat amb nins d’Educació Infantil de diferents escoles públiques de les
Illes Balears. Així mateix, dues experiències, Xishun i Codi de barres, s’han realitzat amb
alumnat de primer cicle d’Educació Primàri
The complex structure of HH 110 as revealed from Integral Field Spectroscopy
HH 110 is a rather peculiar Herbig-Haro object in Orion that originates due
to the deflection of another jet (HH 270) by a dense molecular clump, instead
of being directly ejected from a young stellar object. Here we present new
results on the kinematics and physical conditions of HH 110 based on Integral
Field Spectroscopy. The 3D spectral data cover the whole outflow extent (~4.5
arcmin, ~0.6 pc at a distance of 460 pc) in the spectral range 6500-7000 \AA.
We built emission-line intensity maps of H, [NII] and [SII] and of
their radial velocity channels. Furthermore, we analysed the spatial
distribution of the excitation and electron density from [NII]/H,
[SII]/H, and [SII] 6716/6731 integrated line-ratio maps, as well as
their behaviour as a function of velocity, from line-ratio channel maps. Our
results fully reproduce the morphology and kinematics obtained from previous
imaging and long-slit data. In addition, the IFS data revealed, for the first
time, the complex spatial distribution of the physical conditions (excitation
and density) in the whole jet, and their behaviour as a function of the
kinematics. The results here derived give further support to the more recent
model simulations that involve deflection of a pulsed jet propagating in an
inhomogeneous ambient medium. The IFS data give richer information than that
provided by current model simulations or laboratory jet experiments. Hence,
they could provide valuable clues to constrain the space parameters in future
theoretical works.Comment: 12 pages, 15 figures Accepted in MNRA
A survey of IRAS young stellar object candidates: Searching for large-scale Herbig-Haro objects
Context. Jets and outflows are associated with young stellar objects across the stellar mass spectrum, from brown dwarf protostars to massive Ae/Be stars. Frequently the jet morphology is spatially discontinuous because of the temporal variability of the ejection from the driving source. Images covering a wide field of view around the jet-driving source are useful to map the large-scale jet emission and to explore the mass ejection history. Aims. The aim of our work was to search for large-scale optical Herbig-Haro (HH) objects lying in a wide field around a sample of IRAS sources, which are candidates to trace young stellar objects. Methods. Deep narrowband images through the Hα and [S II ] emission lines, and through an off-line continuum filter, covering a wide (∼15 0 ) field around the IRAS targets were acquired. The images in the three filters were analyzed to identify shock-excited line emission (i.e., HH) in contrast to scattered line emission. Results. New images of a sample of 15 IRAS sources, obtained in a homogeneous way are presented. HH emission was detected in six fields, and the astrometry of the knot features is given. The nature of the extended emission as scattered emission around nine of the IRAS targets is confirmed. For seven IRAS sources with unclear optical counterparts, a more plausible counterpart is proposed. A refined value of the source distance is reported for seven targets. An update of the main data available for each of the sampled fields, including images from public data archives, is also presented
Muestreador sumergible de materia orgánica disuelta y particulada en medios acuáticos
Fecha de presentación nacional 04-08-1988.-- Titular: Consejo Superior de Investigaciones científicas (CSIC).El equipo que se presenta permite el muestreo directo de los compuestos orgánicos disueltos y particulados en aguas profundas y el registro simultáneo de las caracteristícas de la masa de agua muestreada (volumen, profundidad, dirección e intensidad de la corriente salinidad, temperatura, etc...). El equipo es sumergible y se basa en la filtración "in situ" de grandes volúmenes de agua mediante una bomba impelente no contaminante y subsiguiente extracción de la fase disuelta mediante adsorción sobre un soporte polimérico. El sistema opera conectado por un cable eléctrico polifásico a un panel de mandos y recogida de datos. Los fi ltros y adsorbentes son posteriormente analizados en el laboratorio. El sistema es de aplicación en numerosos campos de actividad que requieren la investigación o control de masas de agua como la oceanografía, acuicultura, medio ambiente, etc.Peer reviewe
Padina ditristromatica and Padina pavonicoides (Dictyotales, Phaeophyceae): two new records for the marine benthic flora of the Mediterranean Spanish coasts
Padina distristromatica Ni-Ni-Win & H. Kawai and Padina pavonicoides Ni-Ni-Win & H. Kawai, two species recently described from the Mediterranean Sea, are reported for the first time from the coasts of the Iberian Peninsula, and the former also from the Balearic Islands. In this paper new data are provided for both species, especially cell dimensions. The indusium features, which are proposed as new taxonomical character for P. distristromatica, as well as the lack of stolon-like structures in this species, are considered useful features for distinguishing P. distristromatica from P. pavonica. A distribution map of both species in the Spanish coasts is also provided
Competing risks methods
Competing risks data usually arises in studies in which the failure of an individual may be classified into one of k (k > 1) mutually exclusive causes of failure. When competing risks are present, classical survival analysis techniques may not be appropriate to use. The main goal of this paper is to review the specific methods to deal with competing risks. To this aim, we first focus on how to specify a competing risks model, which is the structure of observed data in this framework, and
how components of the model are estimated from a given random sample. In addition, we discuss how to correctly interpret probabilities in the presence of competing risks, and regression models are
considered in detail. To conclude, we illustrate the problem with data from a bladder cancer study
Kinematics of the H2O masers at the centre of the PN K3-35
We have studied the kinematics traced by the water masers located at the
centre of the planetary nebula (PN) K3-35, using data from previous Very Large
Array (VLA) observations. An analysis of the spatial distribution and
line-of-sight velocities of the maser spots allows us to identify typical
patterns of a rotating and expanding ring in the position-velocity diagrams,
according to our kinematical model. We find that the distribution of the masers
is compatible with tracing a circular ring with a ~0.021 arcsec (~100 AU)
radius, observed with an inclination angle with respect to the line of sight of
55 degrees. We derive expansion and rotation velocities of 1.4 and 3.1 km/s,
respectively. The orientation of the ring projected on the plane of the sky, at
PA 158 degrees, is almost orthogonal to the direction of the innermost region
of the jet observed in K3-35, suggesting the presence of a disc or torus that
may be related to the collimation of the outflow.Comment: 7 pages, 4 figures, 2 tables. Accepted by MNRA
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