3,387 research outputs found

    All Maximally Entangled Four Qubits States

    Full text link
    We find an operational interpretation for the 4-tangle as a type of residual entanglement, somewhat similar to the interpretation of the 3-tangle. Using this remarkable interpretation, we are able to find the class of maximally entangled four-qubits states which is characterized by four real parameters. The states in the class are maximally entangled in the sense that their average bipartite entanglement with respect to all possible bi-partite cuts is maximal. We show that while all the states in the class maximize the average tangle, there are only few states in the class that maximize the average Tsillas or Renyi α\alpha-entropy of entanglement. Quite remarkably, we find that up to local unitaries, there exists two unique states, one maximizing the average α\alpha-Tsallis entropy of entanglement for all α≥2\alpha\geq 2, while the other maximizing it for all 0<α≤20<\alpha\leq 2 (including the von-Neumann case of α=1\alpha=1). Furthermore, among the maximally entangled four qubits states, there are only 3 maximally entangled states that have the property that for 2, out of the 3 bipartite cuts consisting of 2-qubits verses 2-qubits, the entanglement is 2 ebits and for the remaining bipartite cut the entanglement between the two groups of two qubits is 1ebit. The unique 3 maximally entangled states are the 3 cluster states that are related by a swap operator. We also show that the cluster states are the only states (up to local unitaries) that maximize the average α\alpha-Renyi entropy of entanglement for all α≥2\alpha\geq 2.Comment: 15 pages, 2 figures, Revised Version: many references added, an appendix added with a statement of the Kempf-Ness theore

    Learning the Structure of Deep Sparse Graphical Models

    Full text link
    Deep belief networks are a powerful way to model complex probability distributions. However, learning the structure of a belief network, particularly one with hidden units, is difficult. The Indian buffet process has been used as a nonparametric Bayesian prior on the directed structure of a belief network with a single infinitely wide hidden layer. In this paper, we introduce the cascading Indian buffet process (CIBP), which provides a nonparametric prior on the structure of a layered, directed belief network that is unbounded in both depth and width, yet allows tractable inference. We use the CIBP prior with the nonlinear Gaussian belief network so each unit can additionally vary its behavior between discrete and continuous representations. We provide Markov chain Monte Carlo algorithms for inference in these belief networks and explore the structures learned on several image data sets.Comment: 20 pages, 6 figures, AISTATS 2010, Revise

    Strategies for Vaccination and Control of Apicomplexan Protozoan Parasites

    Full text link
    Over the past several decades a great deal of effort has been invested in developing new control and vaccination strategies for apicomplexan protozoan parasites. These organisms are the cause of some of the most significant and harmful diseases in both humans and animals worldwide and include as examples; Plasmodium (malaria) and Cryptosporidium in humans, Toxoplasma in humans and animals, Babesia and Neospora in cattle, and Eimeria the cause of coccidiosis in animals (poultry, sheep, cattle, etc.). In spite of a great deal of progress made in understanding at the molecular level how these organisms invade, survive and transmit in their respective hosts, there has been a paucity of new vaccines commercially developed against these parasitic protozoa over the past few decades. In this chapter, we will discuss the types of strategies being developed to help control these parasites, which includes the development of live and subunit (both native and recombinant DNA based) vaccines, the search for and use of new or existing drugs (such as artemisinin combination therapy against malaria), as well as simpler management & hygiene strategies that can be employed to help alleviate the burden of parasitic diseases

    Entanglement of subspaces in terms of entanglement of superpositions

    Full text link
    We investigate upper and lower bounds on the entropy of entanglement of a superposition of bipartite states as a function of the individual states in the superposition. In particular, we extend the results in [G. Gour, arxiv.org:0704.1521 (2007)] to superpositions of several states rather than just two. We then investigate the entanglement in a subspace as a function of its basis states: we find upper bounds for the largest entanglement in a subspace and demonstrate that no such lower bound for the smallest entanglement exists. Finally, we consider entanglement of superpositions using measures of entanglement other than the entropy of entanglement.Comment: 7 pages, no figure

    Use of fluorescent nanoparticles to investigate nutrient acquisition by developing Eimeria maxima macrogametocytes

    Get PDF
    The enteric disease coccidiosis, caused by the unicellular parasite Eimeria, is a major and reoccurring problem for the poultry industry. While the molecular machinery driving host cell invasion and oocyst wall formation has been well documented in Eimeria, relatively little is known about the host cell modifications which lead to acquisition of nutrients and parasite growth. In order to understand the mechanism(s) by which nutrients are acquired by developing intracellular gametocytes and oocysts, we have performed uptake experiments using polystyrene nanoparticles (NPs) of 40 nm and 100 nm in size, as model NPs typical of organic macromolecules. Cytochalasin D and nocodazole were used to inhibit, respectively, the polymerization of the actin and microtubules. The results indicated that NPs entered the parasite at all stages of macrogametocyte development and early oocyst maturation via an active energy dependent process. Interestingly, the smaller NPs were found throughout the parasite cytoplasm, while the larger NPs were mainly localised to the lumen of large type 1 wall forming body organelles. NP uptake was reduced after microfilament disruption and treatment with nocodazole. These observations suggest that E. maxima parasites utilize at least 2 or more uptake pathways to internalize exogenous material during the sexual stages of development

    Novel screening test for celiac disease using peptide functionalised gold nanoparticles

    Get PDF
    © The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved. AIM To develop a screening test for celiac disease based on the coating of gold nanoparticles with a peptide sequence derived from gliadin, the protein that triggers celiac disease. METHODS 20 nm gold nanoparticles were first coated with NeutrAvidin. A long chain Polyethylene glycol (PEG) linker containing Maleimide at the Ω-end and Biotin group at the α-end was used to ensure peptide coating to the gold nanoparticles. The maleimide group with the thiol (-SH) side chain reacted with the cysteine amino acid in the peptide sequence and the biotinylated and PEGylated peptide was added to the NeutrAvidin coated gold nanoparticles. The peptide coated gold nanoparticles were then converted into a serological assay. We used the peptide functionalised gold nanoparticle-based assay on thirty patient serum samples in a blinded assessment and compared our results with the previously run serological and pathological tests on these patients. RESULTS A stable colloidal suspension of peptide coated gold nanoparticles was obtained without any aggregation. An absorbance peak shift as well as color change was caused by the aggregation of gold nanoparticles following the addition of anti-gliadin antibody to peptide coated nanoparticles at levels associated with celiac disease. The developed assay has been shown to detect anti-gliadin antibody not only in quantitatively spiked samples but also in a small-scale study on real non-hemolytic celiac disease patient’s samples. CONCLUSION The study demonstrates the potential of gold nanoparticle-peptide based approach to be adapted for developing a screening assay for celiac disease diagnosis. The assay could be a part of an exclusion based diagnostic strategy and prove particularly useful for testing high celiac disease risk populations

    Creativity, ambiguous figures, and academic preference

    Get PDF
    Research suggests that ambiguous figure reversal is associated with creativity, but current evidence relies on subjective self-report that is difficult to quantify (Wiseman, Watt, Gilhooly, Georgiou, 2011 British Journal of Psychology 102 615-622). Using quantifiable measures of both phenomena we confirm this claim. We also find that participants studying science experience much more frequent reversal-a novel and intriguing finding. Keywords: ambiguous figure reversal, creativity, academic preferenc
    • …
    corecore