First record of Poecilochirus mrciaki Mašán, 1999 (Acari, Parasitidae) and its phoretic carriers in the Iberian peninsula

We report for the first time the presence of Poecilochirus mrciaki Mašán, 1999 in the South of Europe, in the Iberian peninsula and on new carrier insects. Mites were collected from carrion insects, during a decomposition experiment carried out in the natural park “Aiako Harria” (Errenteria, Gipuzkoa). Most deutonymphs were found on the body of the necrophagous beetle Necrodes littoralis (Coleoptera, Silphidae). Other species of insects in families Geotrupidae, Staphylinidae (Coleoptera) and Calliphoridae (Diptera) were also transporting mites. All carriers were colonising or visiting the pig carcasses. Sampling lasted 3 months in the summers 2009 and 2010. Most mites were sampled from bloat to advanced decay. This is also the first record of P. mrciaki phoretic on flies (Diptera)

Detection of persistent gamma-ray emission toward SS433/W50

The microquasar SS433 features the most energetic jets known in our Galaxy. A large fraction of the jet kinetic power is delivered to the surrounding W50 nebula at the jet termination shock, from which high-energy emission and cosmic-ray production have been anticipated. Here we report on the detection of a persistent gamma-ray signal from the direction of SS433/W50 with the Fermi Large Area Telescope. The steady flux and a narrow spectral energy distribution with a maximum around 250 MeV suggest that gamma-rays are rendered by the bulk jet kinetic power through proton-proton collisions at the SS433/W50 interaction regions. If the same mechanism is operating in other baryon-loaded microquasar jets, their collective contribution may represent a significant fraction of the total galactic cosmic-ray flux at GeV energies.Comment: Accepted for publication in ApJ

An extended finite element method with smooth nodal stress

The enrichment formulation of double-interpolation finite element method (DFEM) is developed in this paper. DFEM is first proposed by Zheng \emph{et al} (2011) and it requires two stages of interpolation to construct the trial function. The first stage of interpolation is the same as the standard finite element interpolation. Then the interpolation is reproduced by an additional procedure using the nodal values and nodal gradients which are derived from the first stage as interpolants. The re-constructed trial functions are now able to produce continuous nodal gradients, smooth nodal stress without post-processing and higher order basis without increasing the total degrees of freedom. Several benchmark numerical examples are performed to investigate accuracy and efficiency of DFEM and enriched DFEM. When compared with standard FEM, super-convergence rate and better accuracy are obtained by DFEM. For the numerical simulation of crack propagation, better accuracy is obtained in the evaluation of displacement norm, energy norm and the stress intensity factor

Statistical extraction of process zones and representative subspaces in fracture of random composite

We propose to identify process zones in heterogeneous materials by tailored statistical tools. The process zone is redefined as the part of the structure where the random process cannot be correctly approximated in a low-dimensional deterministic space. Such a low-dimensional space is obtained by a spectral analysis performed on pre-computed solution samples. A greedy algorithm is proposed to identify both process zone and low-dimensional representative subspace for the solution in the complementary region. In addition to the novelty of the tools proposed in this paper for the analysis of localised phenomena, we show that the reduced space generated by the method is a valid basis for the construction of a reduced order model.Comment: Submitted for publication in International Journal for Multiscale Computational Engineerin

El debate entre percepción conceptual y percepción no conceptual a partir de la obra de John McDowell: implicaciones epistemológicas

En este trabajo pretendo mostrar que hay una alternativa epistemológicamente viable al conceptualismo de John McDowell, que a su vez entiende los conceptos como entidades eminentemente lingüísticas. Para ello, repaso los debates que McDowell mantuvo con Hubert Dreyfus, Charles Travis y Gareth Evans para argumentar que una teoría de la percepción no conceptualista adecuadamente entendida –concibiendo el proceso de categorización en un sentido no tan lingüísticamente mediado– no tiene por qué sufrir algunos de los problemas epistemológicos que McDowell aduce contra ellas en Mente y mundo.In this work I intend to show that there’s an epistemologically viable alternative to John McDowell’s conceptualism, who in turn understands concepts as being primarily linguistically-mediated entities. To that end, I review McDowell’s debates with Hubert Dreyfus, Charles Travis and Gareth Evans in order to argue that a non-conceptualist theory of perception, adequately understood (involving a process of non-linguistic categorization), doesn’t need to be subject to some of the epistemological objections raised by McDowell in Mind and World.Máster en Lógica y Filosofía de la Cienci

Quantum Error Correction - Decoders

Error correction is used to correct any errors that may arise when sending any message, as errors are prone to appear due to noise. For classical codes, there are many decoders used, for example, belief propagation. Unfortunately, these classical decoders are less efficient for quantum codes. A proposed remedy to improve the decoders efficiency is to use a neural network for decoding. In this thesis, we will implement belief propagation on the toric code and check its efficiency. We will see that for few errors, belief propagation works, but it fails for other cases. We also introduce the modifications needed for neural belief propagation, a modification of the original algorithm that integrates a neural network on the algorithm structure