5,159 research outputs found
Density estimates on a parabolic spde
We consider a general class of parabolic spde's [formula] with (t, x) [member of] [0, T]×[0, 1] and [epsilon]Wt,x, [epsilon] > 0, a perturbed Gaussian space-time white noise. For (t, x) [member of] (0, T]×(0, 1) we prove the called Davies and Varadhan-Léandre estimates of the density p[epsilon]t,x of the solution u[epsilon]t,x
Long slit spectroscopy of a sample of isolated spirals with and without an AGN
We present the kinematical data obtained for a sample of active (Seyfert) and
non active isolated spiral galaxies, based on long slit spectra along several
position angles in the Halpha line region and, in some cases, in the Ca triplet
region as well. Gas velocity distributions are presented, together with a
simple circular rotation model that allows to determine the kinematical major
axes. Stellar velocity distributions are also shown. The main result is that
active and control galaxies seem to be equivalent in all kinematical aspects.
For both subsamples, the departure from pure circular rotation in some galaxies
can be explained by the presence of a bar and/or of a spiral arm. They also
present the same kind of peculiarities, in particular, S-shape structures are
quite common near the nuclear regions. They define very similar Tully-Fisher
relations. Emission line ratios are given for all the detected HII regions; the
analysis of the [NII]/Halpha metallicity indicator shows that active and
non-active galaxies have indistinguishable disk metallicities. These results
argue in favour of active and non-active isolated spiral galaxies having
essentially the same properties, in agreement with our previous results based
on the analysis of near infrared images. It appears now necessary to confirm
these results on a larger sample.Comment: 35 pages, 54 figures, Accepted for publication in Astronomy &
Astrophysics The full paper with its figures is available on the anonymous
account of ftp.iap.fr in /home/ftp/pub/from_users/durret/marquez.ps.gz (999
kb
Classical properties of algebras using a new graph association
We study the relation between algebraic structures and Graph Theory. We have
defined five different weighted digraphs associated to a finite dimensional
algebra over a field in order to tackle important properties of the associated
algebras, mainly the nilpotency and solvability in the case of Leibniz
algebras
A new battery-charging method suggested by molecular dynamics simulations
Based on large-scale molecular dynamics simulations, we propose a new
charging method that should be capable of charging a Lithium-ion battery in a
fraction of the time needed when using traditional methods. This charging
method uses an additional applied oscillatory electric field. Our simulation
results show that this charging method offers a great reduction in the average
intercalation time for Li+ ions, which dominates the charging time. The
oscillating field not only increases the diffusion rate of Li+ ions in the
electrolyte but, more importantly, also enhances intercalation by lowering the
corresponding overall energy barrier.Comment: 11 pages, 5 figure
Computing coset leaders and leader codewords of binary codes
In this paper we use the Gr\"obner representation of a binary linear code
to give efficient algorithms for computing the whole set of coset
leaders, denoted by and the set of leader codewords,
denoted by . The first algorithm could be adapted to
provide not only the Newton and the covering radius of but also to
determine the coset leader weight distribution. Moreover, providing the set of
leader codewords we have a test-set for decoding by a gradient-like decoding
algorithm. Another contribution of this article is the relation stablished
between zero neighbours and leader codewords
Valor nutricional de los ácidos grasos de los peces de agua dulce neotropicales Prochilodus magdalenae, Pseudoplatystoma magdaleniatum y Ageneiosus pardalis
This study aimed to determine the nutritional value of the fatty acids in the freshwater fish Prochilodus magdalenae, Pseudoplatystoma magdaleniatum and Ageneiosus pardalis during dry and wet Neotropical seasons with the view to generate useful information for nutrition and sustainable commercial exploitation. The analysis of fatty acids was performed by gas chromatography–mass spectrometry and the nutritional value was calculated using five estimators: n-6/n-3 ratio, unsaturation index (UI), atherogenicity index (AI), thrombogenicity index (TI) and ratio of hypocholesterolemic/hypercholesterolemic (h/H) fatty acids. A different number of fatty acids (P. magdaleniatum = 50, P. magdalenae = 41, and A. pardalis = 32) was identified for each species and the average abundance percentages were different in the two seasons (p < 0.05). Prochilodus magdalenae and P. magdaleniatum showed healthy n-6/n-3 ratios (1.04 and 2.72) in the different seasons. Although the three species showed low values of UI (0.37–0.63), the remaining nutritional indexes were within the healthy range (AI: 0.04–0.70, TI: 0.66–1.07, h/H: 0.80 – 24.40). Multivariate analysis showed similar healthy nutritional values for the species, with exception of P. magdaleniatum.En este estudio se determinó el valor nutricional de ácidos grasos presentes en las especies P. magdaleniatum, P. magdalenae y A. pardalis en los periodos lluvioso y seco, con el fin de generar información útil para una nutrición saludable y una explotación comercial sostenible. El análisis de los ácidos grasos se realizó por CG-EM y el valor nutricional se estimó mediante relación n-6/n-3, índices de insaturación (II), aterogenicidad (IA), trombogenicidad (IT) y relación de ácidos grasos hipocolesterolémicos/hipercolesterolémicos (h/H). Se identificaron números diferentes de ácidos grasos en cada especie (P. magdaleniatum = 50, P. magdalenae = 41 and A. pardalis = 32) y las medias de los porcentajes mayoritarios fueron diferentes en los dos periodos (p < 0,05). Las especies P. magdalenae y P. magdaleniatum mostraron relaciones n-6/n-3 saludables (1,04 y 2,72) en periodos diferentes. Aunque las tres especies mostraron valores II bajos (0,37-0,63), los demás índices IA (0,04-0,70), TI (0,66-1,07) y h/H (0,80 – 24,40) están dentro del rango saludable. El análisis multivariante mostró valores nutricionales similares en dos especies excepto P. magdaleniatum
Health week: an experience of working with the circle
Enfermera y profesora en el IES Castillo de Matrera de Villamartín en la provincia de Cádiz, desarrollo mi labor docente con alumnos y alumnas de los Ciclos Formativos: Técnico Superior de Laboratorio Diagnóstico Clínico y con Auxiliares de Enfermería (Ciclo de Grado Medio).
La experiencia que presento a continuación, es la denominada “Semana Sanitaria”. Acción que se organiza como actividad complementaria desde hace varios años en el centro y que se dirige al alumnado de los ciclos formativos en los que imparto docencia, con la intención de que los alumnos/as se familiaricen con el mundo laboral que próximamente les espera. Esto lo llevamos a cabo contactando con diferentes centros, asociaciones y empresas del entorno y dándoles a conocer a profesionales en activo que les muestren de una manera directa la organización y consecución de sus profesiones.
El motivo que hace que la actividad se repita cada año es la buena acogida y ventajas que aporta tanto a profesores, como a los profesionales que intervienen y principalmente al alumnos/as del centro. Este curso, como coordinadora de la actividad doy las gracias a todos ellos porque sin su colaboración no hubiera sido posible realizar la experiencia y compartir tantas vivencias
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