746 research outputs found
Fundamental Solutions and Decay of Fully Non-local Problems
In this paper, we study a fully non-local reaction-diffusion equation which
is non-local both in time and space. We apply subordination principles to
construct the fundamental solutions of this problem, which we use to find a
representation of the mild solutions. Moreover, using techniques of Harmonic
Analysis and Fourier Multipliers, we obtain the temporal decay rates for the
mild solutions
Supersymmetric Quantum Mechanics, multiphoton algebras and coherent states
The multiphoton algebras for one-dimensional Hamiltonians with infinite
discrete spectrum, and for their associated kth-order SUSY partners are
studied. In both cases, such an algebra is generated by the multiphoton
annihilation and creation operators, as well as by Hamiltonians which are
functions of an appropriate number operator. The algebras obtained turn out to
be polynomial deformations of the corresponding single-photon algebra
previously studied. The Barut-Girardello coherent states, which are eigenstates
of the annihilation operator, are obtained and their uncertainty relations are
explored by means of the associated quadratures.Comment: Last version of the paper, 6 figure
Noncommutative spaces, the quantum of time and the Lorentz symmetry
We introduce three space-times that are discrete in time and compatible with
the Lorentz symmetry. We show that these spaces are no commutative, with
commutation relations similar to the relations of the Snyder and Yang spaces.
Furthermore, using a reparametrized relativistic particle we obtain a
realization of the Snyder type spaces and we construct an action for them.Comment: 8 pages, to appear in PR
A note about the quantum of area in a non-commutative space
In this note we show that in a two-dimensional non-commutative space the area
operator is quantized, this outcome is compared with the result obtained by
Loop Quantum Gravity methods.Comment: 6 pages, references added, minor correction
LA COLONIA DE TRICAHUES (CYANOLISEUS PATAGONUS BLOXAMI, AVES: PSITTACIFORMES) DEL ALTO CACHAPOAL, CHILE: VARIACIONES POBLACIONALES ENTRE 1985 Y 2015
Resumen · El Loro Tricahue (Cyanoliseus patagonus bloxami) es una subespecie endémica de Chile amenazada de extinción, siendo la caza, la captura de pollos para su comercio como mascotas y la pérdida de hábitat sus principales amenazas. Abundante y ampliamente distribuida en el pasado, su población está fragmentada y en 1985 no superaba los 3300 ejemplares. Por medio de censos sistemáticos se estudió la variación temporal en la abundancia de los Tricahues en el río Cachapoal (región de O’Higgins, Chile), entre 1985 y 2015, determinando un aumento poblacional de 217 individuos en 1985 hasta 2979 individuos en 2014–2015. El aumento poblacional se debe probablemente a la creación de la Reserva Nacional Río de los Cipreses, la protección directa de las loreras en época de reproducción y campañas de educación ambiental dirigidas a los habitantes de las localidades cercanas.Abstract · The Burrowing Parrot (Cyanoliseus patagonus bloxami, Aves: Psittaciformes) colony from Alto Cachapoal, Chile: variations in population size between 1985 and 2015 The endangered endemic subspecies of the Burrowing Parrot from Chile (Cyanoliseus patagonus bloxami) is threatened by hunting, pet trade, and loss of its habitat. Abundant and widely distributed in the past, its population has become fragmented and, by 1985, consisted of only about 3300 birds in Chile. Based on a systematic monitoring we studied population dynamics at the Cachapoal River (O’Higgins region, Central Chile), documenting a population increase from 217 individuals in 1985 to 2979 in 2014–2015. This growth is probably related to the creation of the Rio Cipreses National Reserve, as well as the direct protection of its colonies and a campaign of environmental awareness aimed at the local people
Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures
Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. López, J. L. Añamuro, V. Moreno, J. E. L. De Vergara, J. Aracil, C. García, J. P. Fernández-Palacios, and M. Izal, "Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures", in 17th IEEE International Conference on Networks, ICON 2011, p. 89-94This paper describes an implementation of multilayer
techniques using the network infrastructure provided by
FEDERICA, PASITO and OneLab projects. FEDERICA project
provides a network infrastructure, based on virtualization capabilities
in both network and computing resources, which
creates custom-made virtual environments. PASITO is a layer-
2 network that connects universities and research centers in
Spain. OneLab measurements tools allow carrying out highaccuracy
active network measurements. Thanks to FEDERICA
and PASITO, we have a multi-layer architecture where the traffic
is routed based on the measurements of OneLab equipment.
To carry out this experiment, we have developed a Multi-layer
Traffic Engineering manager and an implementation of the Path
Computation Element Protocol to solve the lack of a control plane
in IP oriented networks. This work shows the feasibility of multilayer
techniques as a convenient solution for network operators
and it validates our Path Computation Element implementation.This work has been partially funded by the Spanish Ministry
of Education and Science under project ANFORA (TEC2009-13385), by the Spanish Ministry of Industry, Tourism and
Trade under PASITO project, and by the European Union
under project OneLab2 (FP7-224263). Authors would like
to thank Mauro Campanella (GARR, the project coordinator
of FEDERICA) and Miguel Angel Sotos (RedIris) for their
support to carry out this work
Procalcitonin (PCT) levels for ruling-out bacterial coinfection in ICU patients with influenza: A CHAID decision-tree analysis
Objectives: To define which variables upon ICU admission could be related to the presence of coinfection using CHAID (Chi-squared Automatic Interaction Detection) analysis. Methods: A secondary analysis from a prospective, multicentre, observational study (2009-2014) in ICU patients with confirmed A(H1N1)pdm09 infection. We assessed the potential of biomarkers and clinical variables upon admission to the ICU for coinfection diagnosis using CHAID analysis. Performance of cut-off points obtained was determined on the basis of the binominal distributions of the true (+) and true (−) results. Results: Of the 972 patients included, 196 (20.3%) had coinfection. Procalcitonin (PCT; ng/mL 2.4 vs. 0.5, p < 0.001), but not C-reactive protein (CRP; mg/dL 25 vs. 38.5; p = 0.62) was higher in patients with coinfection. In CHAID analyses, PCT was the most important variable for coinfection. PCT <0.29 ng/mL showed high sensitivity (Se = 88.2%), low Sp (33.2%) and high negative predictive value (NPV = 91.9%). The absence of shock improved classification capacity. Thus, for PCT <0.29 ng/mL, the Se was 84%, the Sp 43% and an NPV of 94% with a post-test probability of coinfection of only 6%. Conclusion: PCT has a high negative predictive value (94%) and lower PCT levels seems to be a good tool for excluding coinfection, particularly for patients without shock
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