911 research outputs found

    Memory B cells and CD8âș lymphocytes do not control seasonal influenza A virus replication after homologous re-challenge of rhesus macaques.

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    This study sought to define the role of memory lymphocytes in the protection from homologous influenza A virus re-challenge in rhesus macaques. Depleting monoclonal antibodies (mAb) were administered to the animals prior to their second experimental inoculation with a human seasonal influenza A virus strain. Treatment with either anti-CD8α or anti-CD20 mAbs prior to re-challenge had minimal effect on influenza A virus replication. Thus, in non-human primates with pre-existing anti-influenza A antibodies, memory B cells and CD8αâș T cells do not contribute to the control of virus replication after re-challenge with a homologous strain of influenza A virus

    Atomic Scale Memory at a Silicon Surface

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    The limits of pushing storage density to the atomic scale are explored with a memory that stores a bit by the presence or absence of one silicon atom. These atoms are positioned at lattice sites along self-assembled tracks with a pitch of 5 atom rows. The writing process involves removal of Si atoms with the tip of a scanning tunneling microscope. The memory can be reformatted by controlled deposition of silicon. The constraints on speed and reliability are compared with data storage in magnetic hard disks and DNA.Comment: 13 pages, 5 figures, accepted by Nanotechnolog

    Anderson Transition in Disordered Graphene

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    We use the regularized kernel polynomial method (RKPM) to numerically study the effect disorder on a single layer of graphene. This accurate numerical method enables us to study very large lattices with millions of sites, and hence is almost free of finite size errors. Within this approach, both weak and strong disorder regimes are handled on the same footing. We study the tight-binding model with on-site disorder, on the honeycomb lattice. We find that in the weak disorder regime, the Dirac fermions remain extended and their velocities decrease as the disorder strength is increased. However, if the disorder is strong enough, there will be a {\em mobility edge} separating {\em localized states around the Fermi point}, from the remaining extended states. This is in contrast to the scaling theory of localization which predicts that all states are localized in two-dimensions (2D).Comment: 4 page

    US-LHC Magnet Database and conventions

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    The US-LHC Magnet Database is designed for production-magnet quality assurance, field and alignment error impact analysis, cryostat assembly assistance, and ring installation assistance. The database consists of tables designed to store magnet field and alignment measurements data and quench data. This information will also be essential for future machine operations including local IR corrections. (7 refs)

    From brand congruence to the ‘virtuous circle’: branding and the commercialization of public service broadcasting

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    In debates about the commercialization of public service broadcasting little attention has been paid to the ways in which the public might experience the commercial and public service activities of public service broadcasters and the impact that this may have on attitudes towards public service broadcasting. This is despite the fact that public service broadcasters increasingly depend on public support for their continued survival. Using the case study of the BBC, this article examines the ways in which the corporation has adopted strategic brand management to negotiate the relationship between its commercial and public service activities. Focusing on specific examples of the BBC’s commercial and public services, the article reveals a tension between the corporation’s attempts to ensure that all activities support its public purposes and its need to ensure separation between public and commercial work. Focusing on the consumer’s experience of the BBC brand, the article argues that rather than seeing commercial activity and public service broadcasting as inherently contradictory, we should be looking at the ways in which public service broadcasters can better communicate the relationship between their commercial and public service activities while continuing to argue for the social and cultural value of publicly funded broadcasting

    Ultracold Neutron Production in a Pulsed Neutron Beam Line

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    We present the results of an Ultracold neutron (UCN) production experiment in a pulsed neutron beam line at the Los Alamos Neutron Scattering Center. The experimental apparatus allows for a comprehensive set of measurements of UCN production as a function of target temperature, incident neutron energy, target volume, and applied magnetic field. However, the low counting statistics of the UCN signal expected can be overwhelmed by the large background associated with the scattering of the primary cold neutron flux that is required for UCN production. We have developed a background subtraction technique that takes advantage of the very different time-of-flight profiles between the UCN and the cold neutrons, in the pulsed beam. Using the unique timing structure, we can reliably extract the UCN signal. Solid ortho-D2_2 is used to calibrate UCN transmission through the apparatus, which is designed primarily for studies of UCN production in solid O2_2. In addition to setting the overall detection efficiency in the apparatus, UCN production data using solid D2_2 suggest that the UCN upscattering cross-section is smaller than previous estimates, indicating the deficiency of the incoherent approximation widely used to estimate inelastic cross-sections in the thermal and cold regimes

    Summary of US-LHC Magnet Database Workshop

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