74 research outputs found

    Paired and semipaired domination in triangulations

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    A dominating set of a graph GG is a subset DD of vertices such that every vertex not in DD is adjacent to at least one vertex in DD. A dominating set DD is paired if the subgraph induced by its vertices has a perfect matching, and semipaired if every vertex in DD is paired with exactly one other vertex in DD that is within distance 2 from it. The paired domination number, denoted by γpr(G)\gamma_{pr}(G), is the minimum cardinality of a paired dominating set of GG, and the semipaired domination number, denoted by γpr2(G)\gamma_{pr2}(G), is the minimum cardinality of a semipaired dominating set of GG. A near-triangulation is a biconnected planar graph that admits a plane embedding such that all of its faces are triangles except possibly the outer face. We show in this paper that γpr(G)2n4\gamma_{pr}(G) \le 2 \lfloor \frac{n}{4} \rfloor for any near-triangulation GG of order n4n\ge 4, and that with some exceptions, γpr2(G)2n5\gamma_{pr2}(G) \le \lfloor \frac{2n}{5} \rfloor for any near-triangulation GG of order n5n\ge 5

    Nota sobre las características estructurales de la zona de "Cueto Negro" (Cordillera Cantábrica)

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    Se citan algunos datos estructurales respecto a la zona comprendida entre los puertos Pajares y La Cubilla (Cordillera Cantábrica). Se destaca la presencia de una ventana tectónica, en la zona de Cueto negro, relacionada con la unidad cabalgante de Bodón, ampliamente replegada. Estos elementos se integran dentro del haz de estructuras que caracterizan el "arco medio" de la Rodilla Astúrica (Cordillera Cantábrica, España)

    Metric Dimension of Maximal Outerplanar Graphs

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    In this paper, we study the metric dimension problem in maximal outerplanar graphs. Concretely, if β(G) denotes the metric dimension of a maximal outerplanar graph G of order n, we prove that 2≤β(G)≤⌈2n5⌉ and that the bounds are tight. We also provide linear algorithms to decide whether the metric dimension of G is 2 and to build a resolving set S of size ⌈2n5⌉ for G. Moreover, we characterize all maximal outerplanar graphs with metric dimension 2

    Neotectonic processes in marine terrace sediments near Canero (Western Asturias)

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    The Pleistocene sediments deposited on the emerged marine abrasion platform near Canero village (Valdés, Asturias) are truncated by reverse faults which are parallel to basement bedding. These structures imply a neotectonic activity with a NW-SE maximum compressive stress, consistent with recent fault population analysis and current seismicity studies. The described deformation corresponds to a reactivation of folds in the Palaeozoic basement through a flexural slip mechanism, with the subsequent accommodation of the unconformable Pleistocene cove

    A Markovian event-based framework for stochastic spiking neural networks

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    In spiking neural networks, the information is conveyed by the spike times, that depend on the intrinsic dynamics of each neuron, the input they receive and on the connections between neurons. In this article we study the Markovian nature of the sequence of spike times in stochastic neural networks, and in particular the ability to deduce from a spike train the next spike time, and therefore produce a description of the network activity only based on the spike times regardless of the membrane potential process. To study this question in a rigorous manner, we introduce and study an event-based description of networks of noisy integrate-and-fire neurons, i.e. that is based on the computation of the spike times. We show that the firing times of the neurons in the networks constitute a Markov chain, whose transition probability is related to the probability distribution of the interspike interval of the neurons in the network. In the cases where the Markovian model can be developed, the transition probability is explicitly derived in such classical cases of neural networks as the linear integrate-and-fire neuron models with excitatory and inhibitory interactions, for different types of synapses, possibly featuring noisy synaptic integration, transmission delays and absolute and relative refractory period. This covers most of the cases that have been investigated in the event-based description of spiking deterministic neural networks

    The Production of a New MAGE-3 Peptide Presented to Cytolytic T Lymphocytes by HLA-B40 Requires the Immunoproteasome

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    By stimulating human CD8+ T lymphocytes with autologous dendritic cells infected with an adenovirus encoding MAGE-3, we obtained a cytotoxic T lymphocyte (CTL) clone that recognized a new MAGE-3 antigenic peptide, AELVHFLLL, which is presented by HLA-B40. This peptide is also encoded by MAGE-12. The CTL clone recognized MAGE-3–expressing tumor cells only when they were first treated with IFN-γ. Since this treatment is known to induce the exchange of the three catalytic subunits of the proteasome to form the immunoproteasome, this result suggested that the processing of this MAGE-3 peptide required the immunoproteasome. Transfection experiments showed that the substitution of β5i (LMP7) for β5 is necessary and sufficient for producing the peptide, whereas a mutated form of β5i (LMP7) lacking the catalytically active site was ineffective. Mass spectrometric analyses of in vitro digestions of a long precursor peptide with either proteasome type showed that the immunoproteasome produced the antigenic peptide more efficiently, whereas the standard proteasome more efficiently introduced cleavages destroying the antigenic peptide. This is the first example of a tumor-specific antigen exclusively presented by tumor cells expressing the immunoproteasome

    Clinical, methodology, and patient/carer expert advice in pediatric drug development by conect4children.

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    Many medicines are used "off-label" in children outside the terms of the license. Feasible pediatric clinical trials are a challenge to design. Conect4children (c4c) is an Innovative Medicines Initiative project to set up a pan-European pediatric clinical trial network aiming to facilitate the development of new medicines for children. To optimize pediatric trial development by promoting innovative trial design, c4c set up a European multidisciplinary advice service, including the voice of young patients and families, tailored to industry and academia. A network of experts was established to provide multidisciplinary advice to trial sponsors. Experts were selected to join clinical and innovative methodology expert groups. A patient and public involvement (PPI) database, to include the expert opinion of patients and parents/carers was formed. A stepwise process was developed: (1) sponsors contact c4c, (2) scoping interview takes place, (3) ad hoc advice group formed, (5) advice meeting held, and (6) advice report provided. Feedback on the process was collected. Twenty-four clinical and innovative methodology expert groups (>400 experts) and a PPI database of 135 registrants were established. As of September 30, 2022, 36 advice requests were received, with 25 requests completed. Clinical and methodology experts and PPI representatives participated in several advice requests. Sponsors appreciated the advice quality and the multidisciplinary experts from different countries, including experts not known before. Experts and PPI participants were generally satisfied with the process. The c4c project has shown successful proof of concept for a service that presents a new framework to plan innovative and feasible pediatric trials
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