5,744 research outputs found
Entangled Coherent State Qubits in an Ion Trap
We show how entangled qubits can be encoded as entangled coherent states of
two-dimensional centre-of-mass vibrational motion for two ions in an ion trap.
The entangled qubit state is equivalent to the canonical Bell state, and we
introduce a proposal for entanglement transfer from the two vibrational modes
to the electronic states of the two ions in order for the Bell state to be
detected by resonance fluorescence shelving methods.Comment: 4 pages, No figures, accepted to PRA, minor chang
Mormon Colonization Scheme for Vancouver Island
"The question of establishing colonies on Vancouver Island, being then under consideration by the British Government, it was thought that if the Latter-day Saints in Great Britain could go there, they might establish a colony or 'stake of Zion' and be under the immediate jurisdiction of the leaders of the church in America. On this account a petition for assistance from the British Government to this end was addressed to Her Majesty Queen Victoria and to every member of the British Parliament.
The role of HER1-HER4 and EGFRvIII in hormone-refractory prostate cancer
<b>Purpose</b>: The role of the type I receptor tyrosine kinase (HER) family in progression of prostate cancer is controversial. Breast cancer studies show that these receptors should be investigated as a family. The current study investigates expression of HER1-HER4 and EGFRvIII in matched hormone-sensitive and hormone-refractory prostate tumors.
<b>Experimental Design</b>: Immunohistochemical analysis was used to investigate protein expression of HER1-HER4, EGFRvIII, and phosphorylated Akt (pAkt) in matched hormone-sensitive and hormone-refractory prostate tumors.
<b>Results</b>: Surprisingly, high HER2 membrane expression in hormone-sensitive tumors was associated with an increased time to biochemical relapse (<i>P</i> = 0.0003), and this translated into longer overall survival (<i>P</i> = 0.0021). Consistent with other studies, HER4 membrane expression in hormone-sensitive tumors was associated with longer time to biochemical relapse (<i>P</i> = 0.042), and EGFRvIII membrane expression was associated with shorter time to biochemical relapse (<i>P</i> = 0.015). An increase in pAkt expression was associated with reduced survival (<i>P</i> = 0.0098). Multivariate analysis showed that HER2 was an independent positive predictive marker of time to relapse in hormone-sensitive prostate tumors (<i>P</i> = 0.014). In contrast, high HER2 expression in hormone-refractory tumors was associated with decreased time to death from biochemical relapse (<i>P</i> = 0.039), and EGFRvIII nuclear expression was associated with decreased time to death from biochemical relapse and decreased overall survival (<i>P</i> = 0.02 and <i>P</i> = 0.005).
<b>Conclusion</b>: These results suggest that the HER family may have multiple roles in prostate cancer, and that expression of the proteins alone is insufficient to predict the biological response that they may elicit
Van der Waals Frictional Drag induced by Liquid Flow in Low- Dimensional Systems
We study the van der Waals frictional drag force induced by liquid flow in
low-dimensional systems (2D and 1D electron systems, and 2D and 1D channels
with liquid). We find that for both 1D and 2D systems, the frictional drag
force induced by liquid flow may be several orders of magnitude larger than the
frictional drag induced by electronic current.Comment: 10 pages, 4 figure
Spectral Effects of Strong Chi-2 Non-Linearity for Quantum Processing
Optical non-linearity can be used for parametric amplification
and producing down-converted entangled photon pairs that have broad
applications. It is known that weak non-linear media exhibit dispersion and
produce a frequency response. It is therefore of interest to know how spectral
effects of a strong crystal affect the performance. Here we model
the spectral effects of the dispersion of a strong crystal and
illustrate how this affects its ability to perform Bell measurements and
influence the performance of a quantum gates that employ such a Bell
measurement. We show that a Dyson series expansion of the unitary operator is
necessary in general, leading to unwanted spectral entanglement. We identify a
limiting situation employing periodic poling, in which a Taylor series
expansion is a good approximation and this entanglement can be removed.Comment: Will be submitted to PR
Selection from read-only memory with limited workspace
Given an unordered array of elements drawn from a totally ordered set and
an integer in the range from to , in the classic selection problem
the task is to find the -th smallest element in the array. We study the
complexity of this problem in the space-restricted random-access model: The
input array is stored on read-only memory, and the algorithm has access to a
limited amount of workspace. We prove that the linear-time prune-and-search
algorithm---presented in most textbooks on algorithms---can be modified to use
bits instead of words of extra space. Prior to our
work, the best known algorithm by Frederickson could perform the task with
bits of extra space in time. Our result separates
the space-restricted random-access model and the multi-pass streaming model,
since we can surpass the lower bound known for the latter
model. We also generalize our algorithm for the case when the size of the
workspace is bits, where . The running time
of our generalized algorithm is ,
slightly improving over the
bound of Frederickson's algorithm. To obtain the improvements mentioned above,
we developed a new data structure, called the wavelet stack, that we use for
repeated pruning. We expect the wavelet stack to be a useful tool in other
applications as well.Comment: 16 pages, 1 figure, Preliminary version appeared in COCOON-201
Sediment resuspension and erosion by vortex rings
Particle resuspension and erosion induced by a vortex ringinteracting with a sediment layer was investigated experimentally using flow visualization (particle image velocimetry), high-speed video, and a recently developed light attenuation method for measuring displacements in bed level. Near-spherical sediment particles were used throughout with relative densities of 1.2–7 and diameters (d)(d) ranging between 90 and 1600 μm1600 μm. Attention was focused on initially smooth, horizontal bedforms with the vortex ring aligned to approach the bed vertically. Interaction characteristics were investigated in terms of the dimensionless Shields parameter, defined using the vortex-ring propagation speed. The critical conditions for resuspension (whereby particles are only just resuspended) were determined as a function of particle Reynolds number (based on the particle settling velocity and dd). The effects of viscous damping were found to be significant for d/δ<15d/δ<15, where δδ denotes the viscous sublayer thickness. Measurements of bed deformation were obtained during the interaction period, for a range of impact conditions. The (azimuthal) mean crater profile is shown to be generally self-similar during the interaction period, except for the most energetic impacts and larger sediment types. Loss of similarity occurs when the local bed slope approaches the repose limit, leading to collapse. Erosion, deposition, and resuspension volumes are analyzed as a function interaction time, impact condition, and sediment size
Are schools and alcohol a good mix? A qualitative study of school principals’ experiences of adults’ alcohol use in Australian secondary schools
Objective: Parents, schools and the broader community influence children’s socialisation to alcohol.
In Australia, the United Kingdom and the United States there have been media reports of adults
consuming alcohol at family focused school events such as fairs and graduations. The aim of this
qualitative study was to describe school principals’ experiences of adults’ use of alcohol at school
events, when children are present.
Design/setting/participants: A qualitative descriptive study was undertaken. Publicly available lists
were used to invite sixty principals from government and Catholic secondary schools in Victoria,
Australia. In-depth interviews were conducted and analysed thematically and reported using the
Consolidated Criteria for Reporting Qualitative Research guidelines.
Results: Fourteen principals (five female, nine male) participated. Most (10) of the participating
principals reported adults’ use of alcohol at events when students were present. Regarding these
events, most principals reported concerns regarding potential harms and responsibility for decision
making about alcohol availability in schools. Some (4) principals believed alcohol should not be
present at such events and this was their practice. Half of the participating schools had recently
made changes to reduce the availability or management of alcohol at school functions.
Conclusions: The findings confirm the common use of alcohol by adults at school events, the
challenges this poses for school principals and suggests consideration needs to be given to
identifying strategies for supporting schools and school principals in decision-making regarding
the conduct of such events
High-sensitivity force measurement using entangled probes
We show the possibility to improve the measurement sensitivity of a weak
force by using two meters in an entangled state. This latter can be achieved by
exploiting radiation pressure effects.Comment: ReVTeX file, 11 pages, 2 eps figure
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