549 research outputs found

    Fast decoders for qudit topological codes

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    Qudit toric codes are a natural higher-dimensional generalization of the well- studied qubit toric code. However, standard methods for error correction of the qubit toric code are not applicable to them. Novel decoders are needed. In this paper we introduce two renormalization group decoders for qudit codes and analyse their error correction thresholds and efficiency. The first decoder is a generalization of a 'hard-decisions' decoder due to Bravyi and Haah (arXiv:1112.3252). We modify this decoder to overcome a percolation effect which limits its threshold performance for many-level quantum systems. The second decoder is a generalization of a 'soft-decisions' decoder due to Poulin and Duclos-Cianci (2010 Phys. Rev. Lett. 104 050504), with a small cell size to optimize the efficiency of implementation in the high dimensional case. In each case, we estimate thresholds for the uncorrelated bit-flip error model and provide a comparative analysis of the performance of both these approaches to error correction of qudit toric codes

    Influenza A virus NS1 gene mutations F103L and M106I increase replication and virulence

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    <p>Abstract</p> <p>Background</p> <p>To understand the evolutionary steps required for a virus to become virulent in a new host, a human influenza A virus (IAV), A/Hong Kong/1/68(H3N2) (HK-wt), was adapted to increased virulence in the mouse. Among eleven mutations selected in the NS1 gene, two mutations F103L and M106I had been previously detected in the highly virulent human H5N1 isolate, A/HK/156/97, suggesting a role for these mutations in virulence in mice and humans.</p> <p>Results</p> <p>To determine the selective advantage of these mutations, reverse genetics was used to rescue viruses containing each of the NS1 mouse adapted mutations into viruses possessing the HK-wt NS1 gene on the A/PR/8/34 genetic backbone. Both F103L and M106I NS1 mutations significantly enhanced growth <it>in vitro </it>(mouse and canine cells) and <it>in vivo </it>(BALB/c mouse lungs) as well as enhanced virulence in the mouse. Only the M106I NS1 mutation enhanced growth in human cells. Furthermore, these NS1 mutations enhanced early viral protein synthesis in MDCK cells and showed an increased ability to replicate in mouse interferon β (IFN-β) pre-treated mouse cells relative to rPR8-HK-NS-wt NS1. The double mutant, rPR8-HK-NS-F103L + M106I, demonstrated growth attenuation late in infection due to increased IFN-β induction in mouse cells. We then generated a rPR8 virus possessing the A/HK/156/97 NS gene that possesses 103L + 106I, and then rescued the L103F + I106M mutant. The 103L + 106I mutations increased virulence by >10 fold in BALB/c mice. We also inserted the avian A/Ck/Beijing/1/95 NS1 gene (the source lineage of the A/HK/156/97 NS1 gene) that possesses 103L + 106I, onto the A/WSN/33 backbone and then generated the L103F + I106M mutant. None of the H5N1 and H9N2 NS containing viruses resulted in increased IFN-β induction. The rWSN-A/Ck/Beijing/1/95-NS1 gene possessing 103L and 106I demonstrated 100 fold enhanced growth and >10 fold enhanced virulence that was associated with increased tropism for lung alveolar and bronchiolar tissues relative to the corresponding L103F and I106M mutant.</p> <p>Conclusions</p> <p>The F103L and M106I NS1 mutations were adaptive genetic determinants of growth and virulence in both human and avian NS1 genes in the mouse model.</p

    Mosquitoborne Infections after Hurricane Jeanne, Haiti, 2004

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    After Hurricane Jeanne in September 2004, surveillance for mosquitoborne diseases in Gonaïves, Haiti, identified 3 patients with malaria, 2 with acute dengue infections, and 2 with acute West Nile virus infections among 116 febrile patients. These are the first reported human West Nile virus infections on the island of Hispaniola

    Ursinus College Alumni Journal, November 1954

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    Two new preceptresses join administrative staff • Ursinus freshman honored by school group • Ursinus college evening school registration increases • Ursinus faculty member presents TV program • Three new members join the Ursinus faculty • Eight-week summer session at Ursinus • 1954-55 academic year opens with 685 students • Williams named dean at Buena Vista College • South Jersey alumni group holds annual dinner dance • Alumni booster group organizes • McKee named dean at New York University • Ursinus colony at University of Delaware • Dr. Robert McAllister directs polio tests • Bunny Harshaw Vosters \u2740 Middle States tennis champion • Dr. Cornelius Weygandt honored by Dr. Wm. J. Phillips • Christian education in India • College supply store under new management • Sports review • 1954 soccer prospects • Women\u27s varsity hockey • Ursinus women\u27s alumni hockey team plays Irish touring team • Ursinus 1954 football squad • Alumni give over $20,000 • Irene Heinly, class secretary explains the success of the class of 1911 • 1954 loyalty fund report • Mr. and Mrs. Kenneth Reinhart attribute the success of \u2749 to the aid of the vice chairmen • Report of 1954 loyalty fund campaign • Contributors for the 1954 loyalty fund campaign • UC Messiah chorus largest in history • Curtain Club plans fall production • News about ourselves • Engagements • Weddings • Births • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1051/thumbnail.jp

    An Architecture for Multi-User Software Development Environments

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    We present an architecture for multi-user software development environments, covering general, process-centered and rule-based MUSDEs. Our architecture is founded on componentization, with particular concern for the capability to replace the synchronization component - to allow experimentation with novel concurrency control mechanisms - with minimal effects on other components while still supporting integration. The architecture has been implemented in the MARVEL SD

    Memorials to the victims of Nazism: the impact on tourists in Berlin

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    This qualitative study explores tourist responses to memorials to the victims of Nazism in Berlin and the impact they have on the tourist experience. The findings are located in the field of study known as dark tourism, of which visiting memorials is a part. The analysis shows that tourists increased their knowledge of the crimes committed by the Nazis, thus fulfilling the educational function of memorials. Tourists were also overwhelmed by their experience; they attested to feelings of sadness, shock, anger, despair and incomprehension. These feelings made it hard for them to resume the role of tourist after their exposure to a memorial. There was acknowledgement of the extent of commemoration practised in Germany
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