4,700 research outputs found
Measurement-driven dynamics for a coherently-excited atom
The phenomenon of telegraphing in a measurement-driven two-level atom was noted in Cresser et al. [Cresser, J.D.; Barnett, S.M.; Jeffers, J.; Pegg, D.T. Opt. Commun. 2006, 264, 352361]. Here we introduce two quantitative measures of telegraphing: one based on the accumulated measurement record and one on the evolution of the quantum state. We use these to analyse the dynamics of the atom over a wide range of parameters. We find, in particular, that the measures provide broadly similar statistics when the measurements are frequent, but differ widely when measurements are sparse. This is in line with intuition, and demonstrates the utility of both measures
The efficient computation of transition state resonances and reaction rates from a quantum normal form
A quantum version of a recent formulation of transition state theory in {\em
phase space} is presented. The theory developed provides an algorithm to
compute quantum reaction rates and the associated Gamov-Siegert resonances with
very high accuracy. The algorithm is especially efficient for
multi-degree-of-freedom systems where other approaches are no longer feasible.Comment: 4 pages, 3 figures, revtex
Is zjudge a better prime for JUDGE than zudge is?:A new evaluation of current orthographic coding models
Tegument Assembly and Secondary Envelopment of Alphaherpesviruses.
Alphaherpesviruses like herpes simplex virus are large DNA viruses characterized by their ability to establish lifelong latent infection in neurons. As for all herpesviruses, alphaherpesvirus virions contain a protein-rich layer called "tegument" that links the DNA-containing capsid to the glycoprotein-studded membrane envelope. Tegument proteins mediate a diverse range of functions during the virus lifecycle, including modulation of the host-cell environment immediately after entry, transport of virus capsids to the nucleus during infection, and wrapping of cytoplasmic capsids with membranes (secondary envelopment) during virion assembly. Eleven tegument proteins that are conserved across alphaherpesviruses have been implicated in the formation of the tegument layer or in secondary envelopment. Tegument is assembled via a dense network of interactions between tegument proteins, with the redundancy of these interactions making it challenging to determine the precise function of any specific tegument protein. However, recent studies have made great headway in defining the interactions between tegument proteins, conserved across alphaherpesviruses, which facilitate tegument assembly and secondary envelopment. We summarize these recent advances and review what remains to be learned about the molecular interactions required to assemble mature alphaherpesvirus virions following the release of capsids from infected cell nuclei.HSV-1 research in the laboratory of CMC is supported by the Leverhulme Trust (Grant RPG-2012-793) and the Biotechnology and Biological Sciences Research Council (Grant BB/M021424/1). SCG is a Sir Henry Dale Fellow jointly funded by the Wellcome Trust and the Royal Society (Grant Number 098406/Z/12/Z)This is the final version of the article. It first appeared from MDPI via http://dx.doi.org/10.3390/v709286
Progress towards arrays of qubits using diamond
The nitrogen vacancy centre (NV{ ) in diamond has promising properties for several applications in quantum computing and sensing. The works described in this thesis each contribute towards our ability to build systems using NV{ . One such aspiration is the capability to build scalable arrays of deterministically placed, high quality qubits which can be accessed optically. NV{ is a potential candidate however the best current method for entangling two NV{ centres requires that each one is in a separate cryostat which is not scalable. This work shows that single NV{ centres can be laser-written in arrays 6-30 µm deep inside of a diamond with spin coherence times that are an order of magnitude longer than previous laser-written NV{ centres and at least as long as naturally-occurring NV{ . This depth is suitable for integration with solid immersion lenses or optical cavities. Depth-dependent T2 measurements reveal which depths avoid surface-induced decoherence. Tens of thousands of these NV{ could be written into one diamond plate. Additionally a _bre coupled, cryogenic, uorescence confocal microscope has been developed to evaluate the possibilities for using scattered nanodiamonds for sensing at low temperatures
Isolation of a Novel Phage with Activity against Streptococcus mutans Biofilms
peer-reviewedStreptococcus mutans is one of the principal agents of caries formation mainly, because of its ability to form biofilms at the tooth surface. Bacteriophages (phages) are promising antimicrobial agents that could be used to prevent or treat caries formation by S. mutans. The aim of this study was to isolate new S. mutans phages and to characterize their antimicrobial properties. A new phage, ɸAPCM01, was isolated from a human saliva sample. Its genome was closely related to the only two other available S. mutans phage genomes, M102 and M102AD. ɸAPCM01 inhibited the growth of S. mutans strain DPC6143 within hours in broth and in artificial saliva at multiplicity of infections as low as 2.5x10-5. In the presence of phage ɸAPCM01 the metabolic activity of a S. mutans biofilm was reduced after 24 h of contact and did not increased again after 48 h, and the live cells in the biofilm decreased by at least 5 log cfu/ml. Despite its narrow host range, this newly isolated S. mutans phage exhibits promising antimicrobial properties
Assessing and monitoring intratumor heterogeneity in glioblastoma: how far has multimodal imaging come?
Glioblastoma demonstrates imaging features of intratumor heterogeneity that result from underlying heterogeneous biological properties. This stems from variations in cellular behavior that result from genetic mutations that either drive, or are driven by, heterogeneous microenvironment conditions. Among all imaging methods available, only T1-weighted contrast-enhancing and T2-weighted fluid-attenuated inversion recovery are used in standard clinical glioblastoma assessment and monitoring. Advanced imaging modalities are still considered emerging techniques as appropriate end points and robust methodologies are missing from clinical trials. Discovering how these images specifically relate to the underlying tumor biology may aid in improving quality of clinical trials and understanding the factors involved in regional responses to treatment, including variable drug uptake and effect of radiotherapy. Upon validation and standardization of emerging MR techniques, providing information based on the underlying tumor biology, these images may allow for clinical decision-making that is tailored to an individual's response to treatment.Stephen Price is funded by a Clinician Scientist Award from the National Institute for Health Research.This is the author accepted manuscript. The final version is available from Future Medicine via http://dx.doi.org/10.2217/cns.15.2
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