2,719 research outputs found

    Quantum networks reveal quantum nonlocality

    Full text link
    The results of local measurements on some composite quantum systems cannot be reproduced classically. This impossibility, known as quantum nonlocality, represents a milestone in the foundations of quantum theory. Quantum nonlocality is also a valuable resource for information processing tasks, e.g. quantum communication, quantum key distribution, quantum state estimation, or randomness extraction. Still, deciding if a quantum state is nonlocal remains a challenging problem. Here we introduce a novel approach to this question: we study the nonlocal properties of quantum states when distributed and measured in networks. Using our framework, we show how any one-way entanglement distillable state leads to nonlocal correlations. Then, we prove that nonlocality is a non-additive resource, which can be activated. There exist states, local at the single-copy level, that become nonlocal when taking several copies of it. Our results imply that the nonlocality of quantum states strongly depends on the measurement context.Comment: 4 + 3 pages, 4 figure

    A protective role for the Lectin CD169/Siglec-1 against a pathogenic murine retrovirus

    Get PDF
    Lymph- and blood-borne retroviruses exploit CD169/Siglec-1-mediated capture by subcapsular sinus and marginal zone metallophilic macrophages for trans-infection of permissive lymphocytes. However, the impact of CD169-mediated virus capture on retrovirus dissemination and pathogenesis in vivo is unknown. In a murine model of the splenomegaly-inducing retrovirus Friend virus complex (FVC) infection, we find that while CD169 promoted draining lymph node infection, it limited systemic spread to the spleen. At the spleen, CD169-expressing macrophages captured incoming blood-borne retroviruses and limited their spread to the erythroblasts in the red pulp where FVC manifests its pathogenesis. CD169-mediated retroviral capture activated conventional dendritic cells 1 (cDC1s) and promoted cytotoxic CD8+ T cell responses, resulting in efficient clearing of FVC-infected cells. Accordingly, CD169 blockade led to higher viral loads and accelerated death in susceptible mouse strains. Thus, CD169 plays a protective role during FVC pathogenesis by reducing viral dissemination to erythroblasts and eliciting an effective cytotoxic T lymphocyte response via cDC1s

    Regulation of pituitary MT1 melatonin receptor expression by gonadotrophin-releasing hormone (GnRH) and early growth response factor-1 (Egr-1) : in vivo and in vitro studies

    Get PDF
    Copyright: © 2014 Bae et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC; grant BB/F020309/1; http://www.bbsrc.ac.uk/home/home.aspx). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

    Get PDF
    Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

    Preclinical discovery of apixaban, a direct and orally bioavailable factor Xa inhibitor

    Get PDF
    Apixaban (BMS-562247; 1-(4-methoxyphenyl)-7-oxo-6-(4-(2-oxopiperidin-1-yl)phenyl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-c]pyridine-3-carboxamide), a direct inhibitor of activated factor X (FXa), is in development for the prevention and treatment of various thromboembolic diseases. With an inhibitory constant of 0.08 nM for human FXa, apixaban has greater than 30,000-fold selectivity for FXa over other human coagulation proteases. It produces a rapid onset of inhibition of FXa with association rate constant of 20 μM−1/s approximately and inhibits free as well as prothrombinase- and clot-bound FXa activity in vitro. Apixaban also inhibits FXa from rabbits, rats and dogs, an activity which parallels its antithrombotic potency in these species. Although apixaban has no direct effects on platelet aggregation, it indirectly inhibits this process by reducing thrombin generation. Pre-clinical studies of apixaban in animal models have demonstrated dose-dependent antithrombotic efficacy at doses that preserved hemostasis. Apixaban improves pre-clinical antithrombotic activity, without excessive increases in bleeding times, when added on top of aspirin or aspirin plus clopidogrel at their clinically relevant doses. Apixaban has good bioavailability, low clearance and a small volume of distribution in animals and humans, and a low potential for drug–drug interactions. Elimination pathways for apixaban include renal excretion, metabolism and biliary/intestinal excretion. Although a sulfate conjugate of Ο-demethyl apixaban (O-demethyl apixaban sulfate) has been identified as the major circulating metabolite of apixaban in humans, it is inactive against human FXa. Together, these non-clinical findings have established the favorable pharmacological profile of apixaban, and support the potential use of apixaban in the clinic for the prevention and treatment of various thromboembolic diseases

    Designation processes and semantic substitutions used by european portuguese children in a vocabulary test

    Get PDF
    This research study focus on the designation processes and semantic substitutions of each word on the vocabulary sub-task from the language test for children – ABFW, standardized in Brazil and adapted to European Portuguese, as well as the comparison of the results obtained in the two countries, to analyze the relevance of their extensibility to the Portuguese population. Methods: The test was applied to 150 children from 5 to 6 years old, of typical development. The test consists of 9 conceptual categories. Each category consists of different words, which were always assessed in the same sequential order. Results: The sample of this study showed a lower performance only in clothes, places and food semantic categories. All the other categories have outperformed the standard. The categories of vocabulary with higher percentage in the right designation of the words were colors and shapes, animals and toys and music instruments. The categories with a higher percentage of substitution processes, from the reference results, were: food and locations. The most recurrent substitution processes were the co-hyponym, words that designate semantic attributes, valorization of the visual stimulus, hypernym and parasynonyms Conclusion: Given the homogeneity of the results of this study with the results obtained with other studies in Brazil, this test reveal potentiality as an instrument for vocabulary assessment in Portugal.Objetivo: Este estudo teve por objetivo a análise e quantificação dos processos de designação e substituição semântica apresentados na prova do vocabulário do Teste de Linguagem Infantil ABFW, padronizado no Brasil e adaptado para Português Europeu (PE), assim como a comparação dos resultados obtidos nos dois países, de forma a analisar a pertinência da sua extensibilidade à população portuguesa. Métodos: A prova foi aplicada a 150 crianças de 5 e 6 anos de idade, de desenvolvimento típico, na Região Norte de Portugal. A prova é constituída por nove categorias conceituais e cada categoria formada por diferentes vocábulos, que foram avaliados sempre pela mesma ordem sequencial. Resultados: A amostra mostrou desempenho inferior, em relação à norma, apenas nas categorias semânticas vestuário, locais e alimentos. Todas as outras categorias revelaram desempenho superior. As categorias do vocabulário que apresentaram maior percentagem de respostas corretas foram: animais, formas e cores e brinquedos e instrumentos musicais. As categorias que apresentaram percentagem superior de processos de substituição, em relação à norma, foram alimentos e locais. Os processos de substituição mais utilizados foram: substituição por co-hipônimo, vocábulos que designam atributos semânticos, valorização do estímulo visual, hiperônimos e parassinônimos. Conclusão: Dada a homogeneidade dos resultados deste estudo com os resultados obtidos em outros estudos no Brasil, esta prova revela potencialidades como instrumento de avaliação do vocabulário em Portugal.This work is funded by CIEd – Research Centre on Education, projects UID/CED/1661/2013 and UID/CED/1661/2016, Institute of Education, University of Minho, through national funds of FCT/MCTESPT.info:eu-repo/semantics/publishedVersio

    Comparing the frequency of common genetic variants and haplotypes between carriers and non-carriers of BRCA1 and BRCA2 deleterious mutations in Australian women diagnosed with breast cancer before 40 years of age

    Get PDF
    BACKGROUND: BRCA1 and BRCA2 mutations are found in a proportion of families with multiple early-onset breast cancers. There are a large number of different deleterious mutations in both genes, none of which would be detectable using standard genetic association studies. Single common variants and haplotypes of common variants may capture groups of deleterious mutations since some low prevalence haplotypes of common variants occur more frequently among chromosomes that carry rare, deleterious mutations than chromosomes that do not. METHODS: DNA sequence data for BRCA1 and BRCA2 was obtained from 571 participants from the Australian Breast Cancer Family Study. Genetic variants were classified as either deleterious mutations or common genetic variants. Variants tagging common polymorphisms were selected and haplotypes resolved using Haploview. Their frequency was compared to those with and without deleterious mutations using a permutation test. RESULTS: A common genetic variant in BRCA1 (3232A > G) was found to be over-represented in deleterious mutation carriers (p = 0.05), whereas a common genetic variant in BRCA2 (1342A > C) occurred less frequently in deleterious mutation carriers (p = 0.04). All four of the common BRCA1 variants used to form haplotypes occurred more frequently in the deleterious mutation carriers when compared to the non-carriers, but there was no evidence of a difference in the distributions between the two groups (p = 0.34). In BRCA2, all four common variants were found to occur less frequently in the deleterious mutation carriers when compared to non-carriers, but the evidence for difference in the distribution between the two groups was weak (p = 0.16). Several less common haplotypes of common BRCA1 variants were found to be over-represented among deleterious mutation carriers but there was no evidence for this at the population level. In BRCA2, only the most common haplotype was found to occur more frequently in deleterious mutation carriers, with again no evidence at the population level. CONCLUSIONS: We observed differences in the frequency of common genetic variants of the BRCA1 and BRCA2 and their haplotypes between early-onset breast cancer cases who did and did not carry deleterious mutations in these genes. Although our data provide only weak evidence for a difference in frequencies at the population level, the number of deleterious mutation carriers was low and the results may yet be substantiated in a larger study using pooled data
    corecore