Adiabatic Gate Teleportation

The difficulty in producing precisely timed and controlled quantum gates is a significant source of error in many physical implementations of quantum computers. Here we introduce a simple universal primitive, adiabatic gate teleportation, which is robust to timing errors and many control errors and maintains a constant energy gap throughout the computation above a degenerate ground state space. Notably this construction allows for geometric robustness based upon the control of two independent qubit interactions. Further, our piecewise adiabatic evolution easily relates to the quantum circuit model, enabling the use of standard methods from fault-tolerance theory for establishing thresholds.Comment: 4 pages, 1 figure, with additional 3 pages and 2 figures in an appendix. v2 Refs added. Video abstract available at http://www.quantiki.org/video_abstracts/0905090

Arkansas Small-Grain Cultivar Performance Tests 2004-2005

Small-grain cultivar performance tests are conducted each year in Arkansas by the Arkansas Agricultural Experiment Station, Department of Crop, Soil and Environmental Sciences. The tests provide information to companies developing cultivars and/or marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating cultivar recommendations for smallgrain producers

Recurrence rates for SIDS - the importance of risk stratification

Objective: To investigate the importance of stratification by risk factors in computing the probability of a second SIDS in a family. Design: Simulation Study Background: The fact that a baby dies suddenly and unexpectedly means that there is a raised probability that the baby’s family have risk factors associated with Sudden Infant Death Syndrome (SIDS). Thus one cannot consider the risk of a subsequent death to be that of the general population. The Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI)6 identified three major social risk factors: smoking, age1, and unemployed/unwaged as major risk factors. It gave estimates of risk for families with different numbers of these risk factors. We investigate whether it is reasonable to assume that, conditional on these risk factors, the risk of a second event is independent of the risk of the first and as a consequence one can square the risks to get the risk of two SIDS in a family. We have used CESDI data to estimate the probability of a second SID in a family under different plausible scenarios of the prevalence of the risk factors. We have applied the model to make predictions in the Care of Next Infant (CONI) study7. Results: The model gave plausible predictions. The CONI study observed 18 second SIDS. Our model predicted 14 (95% prediction interval 7 to 21). Conclusion: When considering the risk of a subsequent SIDS in a family one should always take into account the known risk factors. If all risks have been identified, then conditional on these risks, the risk of two events is the product of the individual risks However for a given family we cannot quantify the magnitude of the increased risk because of other possible risk factors not accounted for in the model

Performance for futures (Intellectual Output 3)

Performance for Futures students are invite to experiment with a more embodied way of using the future by means of three powerful theatric ‘acts’. In ACT 1 students can experiment with the concept of status, which may increase self-awareness about their status (and that of others) in challenging situations, and empower them to take conscious action to positively affect it. In ACT 2 students are invited to engage with devising and dramaturgy, two stages in a theatre-making process, and perform a variety of futures for themselves to discover how they relate to these futures. In ACT 3 students will be introduced to image theatre techniques that will help them get ‘out of their heads’ and ‘into their bodies’. Embodying their imagined futures will allow them to give actual, physical shape to their emotions and feelings related to their imagined futures

Some New Hypotheses as to Different States of Matter

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ZAP -- Enhanced PCA Sky Subtraction for Integral Field Spectroscopy

We introduce Zurich Atmosphere Purge (ZAP), an approach to sky subtraction based on principal component analysis (PCA) that we have developed for the Multi Unit Spectrographic Explorer (MUSE) integral field spectrograph. ZAP employs filtering and data segmentation to enhance the inherent capabilities of PCA for sky subtraction. Extensive testing shows that ZAP reduces sky emission residuals while robustly preserving the flux and line shapes of astronomical sources. The method works in a variety of observational situations from sparse fields with a low density of sources to filled fields in which the target source fills the field of view. With the inclusion of both of these situations the method is generally applicable to many different science cases and should also be useful for other instrumentation. ZAP is available for download at http://muse-vlt.eu/science/tools.Comment: 12 pages, 7 figures, 1 table. Accepted to MNRA

Weak Gravitational Flexion

Flexion is the significant third-order weak gravitational lensing effect responsible for the weakly skewed and arc-like appearance of lensed galaxies. Here we demonstrate how flexion measurements can be used to measure galaxy halo density profiles and large-scale structure on non-linear scales, via galaxy-galaxy lensing, dark matter mapping and cosmic flexion correlation functions. We describe the origin of gravitational flexion, and discuss its four components, two of which are first described here. We also introduce an efficient complex formalism for all orders of lensing distortion. We proceed to examine the flexion predictions for galaxy-galaxy lensing, examining isothermal sphere and Navarro, Frenk & White (NFW) profiles and both circularly symmetric and elliptical cases. We show that in combination with shear we can precisely measure galaxy masses and NFW halo concentrations. We also show how flexion measurements can be used to reconstruct mass maps in 2-D projection on the sky, and in 3-D in combination with redshift data. Finally, we examine the predictions for cosmic flexion, including convergence-flexion cross-correlations, and find that the signal is an effective probe of structure on non-linear scales.Comment: 17 pages, including 12 figures, submitted to MNRA

Sailing stones on Racetrack Playa

Racetrack Playa in Death Valley, California is home to a group of stones which have, on occasion, slid hundreds of meters across the dry lake bed. New data on wind shear from a similar playa, Owens Dry Lake, about 80 km SSE of Racetrack Playa, and data on the velocities of wind gusts across these playas are consistent with threshold coefficients of static friction that allow for the motion of 30 of the 31 rocks for which data are available

Probing the presence of a single or binary black hole in the globular cluster NGC 6752 with pulsar dynamics

The five millisecond pulsars that inhabit NGC 6752 display locations or accelerations that are quite unusual compared to all other pulsars known in globular clusters. In particular PSR-A, a binary pulsar, lives in the cluster halo, while PSR-B and PSR-E, located in the core, show remarkably high negative spin derivatives. This is suggestive that some uncommon dynamical process is at play in the cluster core that we attribute to the presence of a massive perturber. We here investigate whether a single intermediate-mass black hole, lying on the extrapolation of the Mass versus Sigma relation observed in galaxy spheroids, or a less massive binary consisting of two black holes could play the requested role. To this purpose we simulated binary-binary encounters involving PSR-A, its companion star, and the black hole(s). Various scenarios are discussed in detail. In our close 4-body encounters, a black hole-black hole binary may attract on a long-term stable orbit a millisecond pulsar. Timing measurements on the captured satellite-pulsar, member of a hierarchical triplet, could unambiguously unveil the presence of a black hole(s) in the core of a globular cluster.Comment: 13 pages, 8 figures, Accepted for publication in The Astrophysical Journa