2,582 research outputs found
Feed-forward and its role in conditional linear optical quantum dynamics
Nonlinear optical quantum gates can be created probabilistically using only
single photon sources, linear optical elements and photon-number resolving
detectors. These gates are heralded but operate with probabilities much less
than one. There is currently a large gap between the performance of the known
circuits and the established upper bounds on their success probabilities. One
possibility for increasing the probability of success of such gates is
feed-forward, where one attempts to correct certain failure events that
occurred in the gate's operation. In this brief report we examine the role of
feed-forward in improving the success probability. In particular, for the
non-linear sign shift gate, we find that in a three-mode implementation with a
single round of feed-forward the optimal average probability of success is
approximately given by p= 0.272. This value is only slightly larger than the
general optimal success probability without feed-forward, P= 0.25.Comment: 4 pages, 3 eps figures, typeset using RevTex4, problems with figures
resolve
Identifying evidence-based strategies for reducing suicide in Missoula County: Findings from the Literature
Abstract In 2014, 35 people died by suicide in Missoula County, making this the highest year on record. This gives Missoula County a suicide rate of 31.5; almost three times the national average. Many suicide prevention strategies have been implemented in Missoula County across multiple levels- universal, selective, indicated and comprehensive. A literature review was conducted to identify evidence-based strategies for reducing suicide in Missoula County and to make recommendations for future programs and research. Relevant publications were found in Cochrane Library, SAGE Online Journals and PubMed databases using various search criteria related to suicide prevention. From a review of 21 articles related to suicide prevention strategies, best practices identified as effective were: public awareness campaigns, gatekeeper training, means restriction campaigns, follow-up care programs, and comprehensive awareness and responsiveness programs. A number of evidence-based practices to prevent suicide were identified. Comprehensive suicide prevention programs are especially promising strategies for Missoula County
Characterization of a broad-based mosquito yeast interfering RNA larvicide with a conserved target site in mosquito semaphorin-1a genes
BACKGROUND:
RNA interference (RNAi), which has facilitated functional characterization of mosquito neural development genes such as the axon guidance regulator semaphorin-1a (sema1a), could one day be applied as a new means of vector control. Saccharomyces cerevisiae (baker's yeast) may represent an effective interfering RNA expression system that could be used directly for delivery of RNA pesticides to mosquito larvae. Here we describe characterization of a yeast larvicide developed through bioengineering of S. cerevisiae to express a short hairpin RNA (shRNA) targeting a conserved site in mosquito sema1a genes.
RESULTS:
Experiments conducted on Aedes aegypti larvae demonstrated that the yeast larvicide effectively silences sema1a expression, generates severe neural defects, and induces high levels of larval mortality in laboratory, simulated-field, and semi-field experiments. The larvicide was also found to induce high levels of Aedes albopictus, Anopheles gambiae and Culex quinquefasciatus mortality.
CONCLUSIONS:
The results of these studies indicate that use of yeast interfering RNA larvicides targeting mosquito sema1a genes may represent a new biorational tool for mosquito control
Experimental study of flow past turbine blades
The requirements on gas turbines for aircraft power units, namely, adequate efficiency, operation at high gas temperatures, low weight, and small dimensions, must be taken into consideration during the design of the blading. To secure good efficiency, it is necessary that the gas flow past the blades as smoothly as possible without separation. This is relatively easily obtainable in the accelerated flow of turbine blading, if the blade spacing is chosen small enough. A small blade spacing, however, is detrimental to the other requirements outlined above. Operation at high gas temperatures usually calls for blade cooling. This cooling is associated with a power input that lowers the turbine efficiency. Since the amount of heat that must be carried off for coding a blade can be influenced rather little, the gross power input for a turbine stage can be reduced by keeping the number of blades to a minimum, that is, with blades of high spacing ratio. But here also a limit is imposed, the exceeding of which is followed by separation of flow. Hence the requirement of finding blade forms on which the flow separates at rather high spacing ratios
Explicit solution of the linearized Einstein equations in TT gauge for all multipoles
We write out the explicit form of the metric for a linearized gravitational
wave in the transverse-traceless gauge for any multipole, thus generalizing the
well-known quadrupole solution of Teukolsky. The solution is derived using the
generalized Regge-Wheeler-Zerilli formalism developed by Sarbach and Tiglio.Comment: 9 pages. Minor corrections, updated references. Final version to
appear in Class. Quantum Gra
Linear Thermal Expansion Coefficient of the NaCl Phase of CsCl
Cesium chloride undergoes a phase change from the low-temperature CsCI structure to the high-temperature NaCI structure at about 469°C.l There is a volume increase of about 16% when the NaCI structure appears.1 The nature of the transition is of interest, as are the physical properties of the high-temperature phase. If sufficient high-temperature phase data are available for CsCI, calculations of the heat of transition can be made more accurately
Atomic entanglement near a realistic microsphere
We study a scheme for entangling two-level atoms located close to the surface
of a dielectric microsphere. The effect is based on medium-assisted spontaneous
decay, rigorously taking into account dispersive and absorptive properties of
the microsphere. We show that even in the weak-coupling regime, where the
Markov approximation applies, entanglement up to 0.35 ebits between two atoms
can be created. However, larger entanglement and violation of Bell's inequality
can only be achieved in the strong-coupling regime.Comment: 16 pages, 4 figures, Late
Energy Norms and the Stability of the Einstein Evolution Equations
The Einstein evolution equations may be written in a variety of equivalent
analytical forms, but numerical solutions of these different formulations
display a wide range of growth rates for constraint violations. For symmetric
hyperbolic formulations of the equations, an exact expression for the growth
rate is derived using an energy norm. This expression agrees with the growth
rate determined by numerical solution of the equations. An approximate method
for estimating the growth rate is also derived. This estimate can be evaluated
algebraically from the initial data, and is shown to exhibit qualitatively the
same dependence as the numerically-determined rate on the parameters that
specify the formulation of the equations. This simple rate estimate therefore
provides a useful tool for finding the most well-behaved forms of the evolution
equations.Comment: Corrected typos; to appear in Physical Review
Spontaneous decay of an excited atom in an absorbing dielectric
Starting from the quantized version of Maxwell's equations for the
electromagnetic field in an arbitrary linear Kramers-Kronig dielectric,
spontaneous decay of the excited state of a two-level atom embedded in a
dispersive and absorbing medium is studied and the decay rate is calculated.
The calculations are performed for both the (Clausius-Mosotti) virtual cavity
model and the (Glauber-Lewenstein) real cavity model. It is shown that owing to
nonradiative decay associated with absorption the rate of spontaneous decay
sensitively depends on the cavity radius when the atomic transition frequency
approaches an absorption band of the medium. Only when the effect of absorption
is fully disregarded, then the familiar local-field correction factors are
recovered.Comment: 28 pages, 6 figures, typeset using RevTe
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