138 research outputs found

    Observation of environment-induced double sudden transitions in geometric quantum correlations

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    Correlations in quantum systems exhibit a rich phenomenology under the effect of various sources of noise. We investigate theoretically and experimentally the dynamics of quantum correlations and their classical counterparts in two nuclear magnetic resonance setups, as measured by geometric quantifiers based on trace-norm. We consider two-qubit systems prepared in Bell diagonal states, and perform the experiments in decohering environments resulting from Bell diagonal-preserving Markovian local noise. We then report the first observation of environment-induced double sudden transitions in the geometric quantum correlations, a genuinely nonclassical effect not observable in classical correlations. The evolution of classical correlations in our physical implementation reveals in turn the finite-time relaxation to a pointer basis under nondissipative decoherence, which we characterize geometrically in full analogy with predictions based on entropic measures.Comment: 5 pages, 2 figures. v2: Minor corrections. Published versio

    Cartografía de la biomasa aérea total en masas de Pinus Radiata D. Don a partir de datos públicos LiDAR-PNOA e inventario forestal nacional

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    La estimación de la biomasa total aérea (en adelante biomasa) es fundamental para conocer la estructura y dinámica de los ecosistemas forestales. El objetivo principal de este trabajo ha sido estimar y cartografiar la biomasa de las masas de Pinus radiata D. Don de la comarca Arratia-Nerbioi (Bizkaia, España), a partir de los datos de teledetección LiDAR (Light Detection And Ranging) del PNOA (Plan Nacional de Ortofotografía Aérea) y los datos de campo del IFN4 (Cuarto Inventario Forestal Nacional). La biomasa fue calculada en 51 parcelas de campo del IFN4 aplicando la ecuación alométrica de Montero et al. (2005). Mediante un análisis multivariante de regresión lineal se generó un modelo predictivo de la biomasa, que fue validado mediante la técnica de validación cruzada dejando un dato fuera. Se obtuvo un coeficiente de determinación de 0, 67. Para seleccionar la resolución de la cartografía final, se realizó un análisis de correlación entre los valores de biomasa de las parcelas y los valores predichos por el modelo aplicando dos tamaños de pixel. The estimation of total aboveground biomass (hereinafter referred as biomass) is required to understand the structure and dynamics of forest ecosystems. The main objective of this study is to estimate and map the biomass of Pinus radiata D. Don forest stands located in the Arratia-Nerbioi region (Bizkaia, Spain). LiDAR remote sensing data from the National Plan for Aerial Ortophotography (PNOA) and the information obtained by the Fourth National Forest Inventory (IFN4) have been used. The biomass was calculated in 51 IFN4 field plots applying the allometric equation from Montero et al. (2005). Finally, a multivariate linear regression analysis allowed the generation of a biomass predictive model, which was validated using the leave one-out cross-validation technique. The coefficient of determination of the model was 0.67. A correlation analysis between the values of biomass at plot-level and the values predicted by different pixel sizes, allowed the selection of the best resolution for mapping

    The sudden change phenomenon of quantum discord

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    Even if the parameters determining a system's state are varied smoothly, the behavior of quantum correlations alike to quantum discord, and of its classical counterparts, can be very peculiar, with the appearance of non-analyticities in its rate of change. Here we review this sudden change phenomenon (SCP) discussing some important points related to it: Its uncovering, interpretations, and experimental verifications, its use in the context of the emergence of the pointer basis in a quantum measurement process, its appearance and universality under Markovian and non-Markovian dynamics, its theoretical and experimental investigation in some other physical scenarios, and the related phenomenon of double sudden change of trace distance discord. Several open questions are identified, and we envisage that in answering them we will gain significant further insight about the relation between the SCP and the symmetry-geometric aspects of the quantum state space.Comment: Lectures on General Quantum Correlations and their Applications, F. F. Fanchini, D. O. Soares Pinto, and G. Adesso (Eds.), Springer (2017), pp 309-33

    Autoantibodies Against Proteins Previously Associated With Autoimmunity in Adult and Pediatric Patients With COVID-19 and Children With MIS-C

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    The antibody profile against autoantigens previously associated with autoimmune diseases and other human proteins in patients with COVID-19 or multisystem inflammatory syndrome in children (MIS-C) remains poorly defined. Here we show that 30% of adults with COVID-19 had autoantibodies against the lung antigen KCNRG, and 34% had antibodies to the SLE-associated Smith-D3 protein. Children with COVID-19 rarely had autoantibodies; one of 59 children had GAD65 autoantibodies associated with acute onset of insulin-dependent diabetes. While autoantibodies associated with SLE/Sjögren’s syndrome (Ro52, Ro60, and La) and/or autoimmune gastritis (gastric ATPase) were detected in 74% (40/54) of MIS-C patients, further analysis of these patients and of children with Kawasaki disease (KD), showed that the administration of intravenous immunoglobulin (IVIG) was largely responsible for detection of these autoantibodies in both groups of patients. Monitoring in vivo decay of the autoantibodies in MIS-C children showed that the IVIG-derived Ro52, Ro60, and La autoantibodies declined to undetectable levels by 45-60 days, but gastric ATPase autoantibodies declined more slowly requiring >100 days until undetectable. Further testing of IgG and/or IgA antibodies against a subset of potential targets identified by published autoantigen array studies of MIS-C failed to detect autoantibodies against most (16/18) of these proteins in patients with MIS-C who had not received IVIG. However, Troponin C2 and KLHL12 autoantibodies were detected in 2 of 20 and 1 of 20 patients with MIS-C, respectively. Overall, these results suggest that IVIG therapy may be a confounding factor in autoantibody measurements in MIS-C and that antibodies against antigens associated with autoimmune diseases or other human proteins are uncommon in MIS-C

    TreeDyn: towards dynamic graphics and annotations for analyses of trees

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    BACKGROUND: Analyses of biomolecules for biodiversity, phylogeny or structure/function studies often use graphical tree representations. Many powerful tree editors are now available, but existing tree visualization tools make little use of meta-information related to the entities under study such as taxonomic descriptions or gene functions that can hardly be encoded within the tree itself (if using popular tree formats). Consequently, a tedious manual analysis and post-processing of the tree graphics are required if one needs to use external information for displaying or investigating trees. RESULTS: We have developed TreeDyn, a tool using annotations and dynamic graphical methods for editing and analyzing multiple trees. The main features of TreeDyn are 1) the management of multiple windows and multiple trees per window, 2) the export of graphics to several standard file formats with or without HTML encapsulation and a new format called TGF, which enables saving and restoring graphical analysis, 3) the projection of texts or symbols facing leaf labels or linked to nodes, through manual pasting or by using annotation files, 4) the highlight of graphical elements after querying leaf labels (or annotations) or by selection of graphical elements and information extraction, 5) the highlight of targeted trees according to a source tree browsed by the user, 6) powerful scripts for automating repetitive graphical tasks, 7) a command line interpreter enabling the use of TreeDyn through CGI scripts for online building of trees, 8) the inclusion of a library of packages dedicated to specific research fields involving trees. CONCLUSION: TreeDyn is a tree visualization and annotation tool which includes tools for tree manipulation and annotation and uses meta-information through dynamic graphical operators or scripting to help analyses and annotations of single trees or tree collections
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