653 research outputs found

    Quantum networks reveal quantum nonlocality

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    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

    Body adiposity index to analyze the percentage of fat in young men aged between 7 and 17 years

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    BACKGROUND: The body adiposity index (BAI), uses anthropometry to estimate percent body fat (%F). However, previous studies have shown that the BAI has limited accuracy for children and adolescents. OBJECTIVE: We propose to develop and validate an adjusted BAI for use in male children and adolescents from 7 to 17 years of age. METHODS: The sample consisted of 141 physically active male children and adolescents (age: 12.5 ± 2.14). The %F was determined by X-ray dual energy absorptometry equipment (DXA) as the standard method and by BAI, using an equation that uses height and hip circumference. Arithmetic modeling was used to adjust the structure of the BAI mathematical model. RESULTS: The BAI arithmetic adjustment was successful, resulting in the mathematical model named in the present study of adjusted body adiposity index (BAIADJ ). BAI and BAIADJ correlated with DXA (r ≤ .70, p  .05). CONCLUSION: The adjusted model of the body adiposity index proves to be an effective tool for the analysis of the fat percentage in young males. In addition, it demonstrated significant degrees of agreement and validity in relation to DXA

    Cdc42 defines apical identity and regulates epithelial morphogenesis by promoting apical recruitment of Par6-aPKC and Crumbs

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    Cdc42 regulates epithelial morphogenesis together with the Par complex (Baz/Par3-Par6-aPKC), Crumbs (Crb/CRB3) and Stardust (Sdt/PALS1). However, how these proteins work together and interact during epithelial morphogenesis is not well understood. To address this issue, we used the genetically amenable Drosophila pupal photoreceptor and follicular epithelium. We show that during epithelial morphogenesis active Cdc42 accumulates at the developing apical membrane and cell-cell contacts, independently of the Par complex and Crb. However, membrane localization of Baz, Par6-aPKC and Crb all depend on Cdc42. We find that although binding of Cdc42 to Par6 is not essential for the recruitment of Par6 and aPKC to the membrane, it is required for their apical localization and accumulation, which we find also depends on Par6 retention by Crb. In the pupal photoreceptor, membrane recruitment of Par6-aPKC also depends on Baz. Our work shows that Cdc42 is required for this recruitment and suggests that this factor promotes the handover of Par6-aPKC from Baz onto Crb. Altogether, we propose that Cdc42 drives morphogenesis by conferring apical identity, Par-complex assembly and apical accumulation of Crb

    Chemical diplomacy in male tilapia: urinary signal increases sex hormone and decreases aggression

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    Androgens, namely 11-ketotestosterone (11KT), have a central role in male fish reproductive physiology and are thought to be involved in both aggression and social signalling. Aggressive encounters occur frequently in social species, and fights may cause energy depletion, injury and loss of social status. Signalling for social dominance and fighting ability in an agonistic context can minimize these costs. Here, we test the hypothesis of a 'chemical diplomacy' mechanism through urinary signals that avoids aggression and evokes an androgen response in receiver males of Mozambique tilapia (Oreochromis mossambicus). We show a decoupling between aggression and the androgen response; males fighting their mirror image experience an unresolved interaction and a severe drop in urinary 11KT. However, if concurrently exposed to dominant male urine, aggression drops but urinary 11KT levels remain high. Furthermore, 11KT increases in males exposed to dominant male urine in the absence of a visual stimulus. The use of a urinary signal to lower aggression may be an adaptive mechanism to resolve disputes and avoid the costs of fighting. As dominance is linked to nest building and mating with females, the 11KT response of subordinate males suggests chemical eavesdropping, possibly in preparation for parasitic fertilizations.info:eu-repo/semantics/publishedVersio

    Forensic dentistry now and in the future

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    Forensic dentistry (odontology) deals with the examination, handling and presentation of dental evidence for the legal system. In the UK this work mainly involves criminal cases but in many other countries its remit also extends to civil litigation. There are four main aspects to forensic dentistry: single body identification, Disaster Victim Identification (DVI), age estimation and bite mark identification and analysis. This article provides a brief introduction to the topics and discusses potential future developments that aim to reduce the subjectivity in the analysis process and simplify presentation of evidence to non-dental parties. CPD/Clinical Relevance: This article highlights ways that dental practitioners can assist legal investigations and, in particular, forensic dentists

    Reactive Oxygen Species Production and Mitochondrial Dysfunction Contribute to Quercetin Induced Death in Leishmania amazonensis

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    BACKGROUND: Leishmaniasis, a parasitic disease caused by protozoa of the genus Leishmania, affects more than 12 million people worldwide. Quercetin has generated considerable interest as a pharmaceutical compound with a wide range of therapeutic activities. One such activity is exhibited against the bloodstream parasite Trypanosoma brucei and amastigotes of Leishmania donovani. However, the mechanism of protozoan action of quercetin has not been studied. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we report here the mechanism for the antileishmanial activity of quercetin against Leishmania amazonensis promastigotes. Quercetin inhibited L. amazonensis promastigote growth in a dose- and time- dependent manner beginning at 48 hours of treatment and with maximum growth inhibition observed at 96 hours. The IC(50) for quercetin at 48 hours was 31.4 µM. Quercetin increased ROS generation in a dose-dependent manner after 48 hours of treatment. The antioxidant GSH and NAC each significantly reduced quercetin-induced cell death. In addition, quercetin caused mitochondrial dysfunction due to collapse of mitochondrial membrane potential. CONCLUSIONS/SIGNIFICANCE: The effects of several drugs that interfere directly with mitochondrial physiology in parasites such as Leishmania have been described. The unique mitochondrial features of Leishmania make this organelle an ideal drug target while minimizing toxicity. Quercetin has been described as a pro-oxidant, generating ROS which are responsible for cell death in some cancer cells. Mitochondrial membrane potential loss can be brought about by ROS added directly in vitro or induced by chemical agents. Taken together, our results demonstrate that quercetin eventually exerts its antileishmanial effect on L. amazonensis promastigotes due to the generation of ROS and disrupted parasite mitochondrial function

    Disclosure of cholesterol recognition motifs in transmembrane domains of the human nicotinic acetylcholine receptor

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    Cholesterol influences ion-channel function, distribution and clustering in the membrane, endocytosis, and exocytic sorting of the nicotinic acetylcholine receptor (AChR). We report the occurrence of a cholesterol recognition motif, here coined “CARC”, in the transmembrane regions of AChR subunits that bear extensive contact with the surrounding lipid, and are thus optimally suited to convey cholesterol-mediated signaling from the latter. Three cholesterol molecules could be docked on the transmembrane segments of each AChR subunit, rendering a total of 15 cholesterol molecules per AChR molecule. The CARC motifs contribute each with an energy of interaction between 35 and 52 kJ.mol−1, adding up to a total of about 200 kJ.mol−1 per receptor molecule, i.e. ∼40% of the lipid solvation free energy/ AChR molecule. The CARC motif is remarkably conserved along the phylogenetic scale, from prokaryotes to human, suggesting that it could be responsible for some of the above structural/functional properties of the AChR
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