2,370 research outputs found

    Quantum entanglement and classical communication through a depolarising channel

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    We analyse the role of entanglement for transmission of classical information through a memoryless depolarising channel. Using the isotropic character of this channel we prove analytically that the mutual information cannot be increased by encoding classical bits into entangled states of two qubits.Comment: 6 pages, 2 figures; contribution to special issue of JMO on the physics of quantum information; 2nd version: slight modifications and improved presentatio

    Following Snowden: A Cross-cultural Study on the Social Impact of Snowden's Revelations

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    Purpose – This paper introduces a cross-cultural study of the views and implications of Snowden's revelations about NSA/GCHQ surveillance practices, undertaken through surveys administered in eight countries. The aims and the academic and social significance are explained and justification offered for the methods used. Design/methodology/approach – Pilot surveys were deployed in two countries, following which revised versions were deployed in eight countries (including new collection in the original pilot countries). Quantitative analysis of suitable answer sets (Yes/No; Likert scales) and quantitative analysis (interpretation of free text answers) were performed. Findings – Through the pilot survey studies conducted in Japan and Spain, the academic significance and validity as well as social significance of the project were confirmed. Social implications – The results of the cross-cultural study are expected to contribute not only to the advance of surveillance studies but also to the enhancement of ordinary, non-technical people's awareness of state surveillance and their proactive approach to protecting their own rights and dignity from covert intrusion by government agencies. Originality/value – This paper clarifies the importance and methodologies of investigating the social impact of Snowden's revelations on youngsters' attitudes toward privacy and state surveillance in a cross-cultural analysis framework. Although a few other studies have looked at the impact of Snowden's revelations, these have mostly focussed on the US, so this is the only study to date considering that impact on a broad international scale, using highly similar surveys to ensure comparability. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

    The application of blockchain algorithms to the management of education certificates

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    Blockchain is a new application technology in many sectors and the same is true in the world of education. Therefore, there is an increasingly emerging need to research blockchain technology, as it is still taking its first steps in different sectors, such as education. This article presents a review of the state of the art of blockchain technology in the education sector, focusing on identifying the advantages, disadvantages, and challenges associated with the introduction of blockchain technology in the education sector. In addition, the implementation of a title certificate solution through blockchain technology through the BeCertify project is presented. In this solution, the development stages of the platform, the system architecture, and the operation of the API have been carried out, resulting in a platform that constitutes the first step towards a more transparent and technologically advanced way of managing the certifications of the students’ qualifications

    An isoform of the giant protein titin is a master regulator of human T lymphocyte trafficking

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    Response to multiple microenvironmental cues and resilience to mechanical stress are essential features of trafficking leukocytes. Here, we describe unexpected role of titin (TTN), the largest protein encoded by the human genome, in the regulation of mechanisms of lymphocyte trafficking. Human T and B lymphocytes express five TTN isoforms, exhibiting cell-specific expression, distinct localization to plasma membrane microdomains, and different distribution to cytosolic versus nuclear compartments. In T lymphocytes, the LTTN1 isoform governs the morphogenesis of plasma membrane microvilli independently of ERM protein phosphorylation status, thus allowing selectin-mediated capturing and rolling adhesions. Likewise, LTTN1 controls chemokine-triggered integrin activation. Accordingly, LTTN1 mediates rho and rap small GTPases activation, but not actin polymerization. In contrast, chemotaxis is facilitated by LTTN1 degradation. Finally, LTTN1 controls resilience to passive cell deformation and ensures T lymphocyte survival in the blood stream. LTTN1 is, thus, a critical and versatile housekeeping regulator of T lymphocyte trafficking

    Gold nanoparticle based double-labeling of melanoma extracellular vesicles to determine the specificity of uptake by cells and preferential accumulation in small metastatic lung tumors

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    Background Extracellular vesicles (EVs) have shown great potential for targeted therapy, as they have a natural ability to pass through biological barriers and, depending on their origin, can preferentially accumulate at defined sites, including tumors. Analyzing the potential of EVs to target specific cells remains challenging, considering the unspecific binding of lipophilic tracers to other proteins, the limitations of fluorescence for deep tissue imaging and the effect of external labeling strategies on their natural tropism. In this work, we determined the cell-type specific tropism of B16F10-EVs towards cancer cell and metastatic tumors by using fluorescence analysis and quantitative gold labeling measurements. Surface functionalization of plasmonic gold nanoparticles was used to promote indirect labeling of EVs without affecting size distribution, polydispersity, surface charge, protein markers, cell uptake or in vivo biodistribution. Double-labeled EVs with gold and fluorescent dyes were injected into animals developing metastatic lung nodules and analyzed by fluorescence/computer tomography imaging, quantitative neutron activation analysis and gold-enhanced optical microscopy. Results We determined that B16F10 cells preferentially take up their own EVs, when compared with colon adenocarcinoma, macrophage and kidney cell-derived EVs. In addition, we were able to detect the preferential accumulation of B16F10 EVs in small metastatic tumors located in lungs when compared with the rest of the organs, as well as their precise distribution between tumor vessels, alveolus and tumor nodules by histological analysis. Finally, we observed that tumor EVs can be used as effective vectors to increase gold nanoparticle delivery towards metastatic nodules. Conclusions Our findings provide a valuable tool to study the distribution and interaction of EVs in mice and a novel strategy to improve the targeting of gold nanoparticles to cancer cells and metastatic nodules by using the natural properties of malignant EVs.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

    The genome of the green anole lizard and a comparative analysis with birds and mammals

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    The evolution of the amniotic egg was one of the great evolutionary innovations in the history of life, freeing vertebrates from an obligatory connection to water and thus permitting the conquest of terrestrial environments. Among amniotes, genome sequences are available for mammals and birds, but not for non-avian reptiles. Here we report the genome sequence of the North American green anole lizard, Anolis carolinensis. We find that A. carolinensis microchromosomes are highly syntenic with chicken microchromosomes, yet do not exhibit the high GC and low repeat content that are characteristic of avian microchromosomes. Also, A. carolinensis mobile elements are very young and diverse—more so than in any other sequenced amniote genome. The GC content of this lizard genome is also unusual in its homogeneity, unlike the regionally variable GC content found in mammals and birds. We describe and assign sequence to the previously unknown A. carolinensis X chromosome. Comparative gene analysis shows that amniote egg proteins have evolved significantly more rapidly than other proteins. An anole phylogeny resolves basal branches to illuminate the history of their repeated adaptive radiations.National Science Foundation (U.S.) (NSF grant DEB-0920892)National Science Foundation (U.S.) (NSF grant DEB-0844624)National Human Genome Research Institute (U.S.

    A High-Resolution Map of Human Evolutionary Constraint Using 29 Mammals

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    The comparison of related genomes has emerged as a powerful lens for genome interpretation. Here we report the sequencing and comparative analysis of 29 eutherian genomes. We confirm that at least 5.5% of the human genome has undergone purifying selection, and locate constrained elements covering ~4.2% of the genome. We use evolutionary signatures and comparisons with experimental data sets to suggest candidate functions for ~60% of constrained bases. These elements reveal a small number of new coding exons, candidate stop codon readthrough events and over 10,000 regions of overlapping synonymous constraint within protein-coding exons. We find 220 candidate RNA structural families, and nearly a million elements overlapping potential promoter, enhancer and insulator regions. We report specific amino acid residues that have undergone positive selection, 280,000 non-coding elements exapted from mobile elements and more than 1,000 primate- and human-accelerated elements. Overlap with disease-associated variants indicates that our findings will be relevant for studies of human biology, health and disease.National Human Genome Research Institute (U.S.)National Institute of General Medical Sciences (U.S.) (Grant number GM82901)National Science Foundation (U.S.). Postdoctural Fellowship (Award 0905968)National Science Foundation (U.S.). Career (0644282)National Institutes of Health (U.S.) (R01-HG004037)Alfred P. Sloan Foundation.Austrian Science Fund. Erwin Schrodinger Fellowshi
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