889 research outputs found
Sampling arbitrary photon-added or photon-subtracted squeezed states is in the same complexity class as boson sampling
Boson sampling is a simple model for non-universal linear optics quantum
computing using far fewer physical resources than universal schemes. An input
state comprising vacuum and single photon states is fed through a Haar-random
linear optics network and sampled at the output using coincidence
photodetection. This problem is strongly believed to be classically hard to
simulate. We show that an analogous procedure implements the same problem,
using photon-added or -subtracted squeezed vacuum states (with arbitrary
squeezing), where sampling at the output is performed via parity measurements.
The equivalence is exact and independent of the squeezing parameter, and hence
provides an entire class of new quantum states of light in the same complexity
class as boson sampling.Comment: 5 pages, 2 figure
Boson sampling with displaced single-photon Fock states versus single-photon-added coherent states---The quantum-classical divide and computational-complexity transitions in linear optics
Boson sampling is a specific quantum computation, which is likely hard to
implement efficiently on a classical computer. The task is to sample the output
photon number distribution of a linear optical interferometric network, which
is fed with single-photon Fock state inputs. A question that has been asked is
if the sampling problems associated with any other input quantum states of
light (other than the Fock states) to a linear optical network and suitable
output detection strategies are also of similar computational complexity as
boson sampling. We consider the states that differ from the Fock states by a
displacement operation, namely the displaced Fock states and the photon-added
coherent states. It is easy to show that the sampling problem associated with
displaced single-photon Fock states and a displaced photon number detection
scheme is in the same complexity class as boson sampling for all values of
displacement. On the other hand, we show that the sampling problem associated
with single-photon-added coherent states and the same displaced photon number
detection scheme demonstrates a computational complexity transition. It
transitions from being just as hard as boson sampling when the input coherent
amplitudes are sufficiently small, to a classically simulatable problem in the
limit of large coherent amplitudes.Comment: 7 pages, 3 figures; published versio
Acroneuria lycorias (Boreal Stonefly, Plecoptera: Perlidae) Emergence Behaviors Discovered in Pinus strobus Canopy
Species of Plecoptera, or stoneflies, are known to use vertical emergence supports, and researchers believe many species of Plecoptera exploit arboreal habitats during emergence. However, the exact nature of these arboreal behaviors has largely remained a mystery. While exploring the habitat potential of Pinus strobus (L.) (Eastern White Pine) canopies in northern Wisconsin we observed Acroneuria lycorias (Newman) (Boreal Stonefly, Plecoptera: Perlidae) exuviae at heights as high as 12m (observations at 6.6, 9, 9.5, and 12m). Most A. lycorias exuviae appeared to have a strong preference for emergence sites at the underside or base of branches similar to some Odonate species. We also observed A. lycorias, adults climbing upwards along the main stem, post-emergence, to heights up to 22m. To our knowledge, these heights represent the greatest heights ever documented for A. lycorias adults and exuviae, or any Plecopteran species. While other researchers have speculated that A. lycorias uses arboreal habitats during emergence, these behaviors were considered almost impossible to describe. Our observations provide us with new insights into Plecopteran emergence behaviors, especially for this species. We propose three alternative hypotheses that may explain these unique emergence behaviors
Implementing and Evaluating the Communities That Care Prevention System in Rural Pennsylvania
Communities That Care (CTC) is a prevention-planning system that helps community members plan, implement, and evaluate evidence-based prevention strategies that target common behavioral problems among youth. Recent evaluations of the system have indicated promising results. To date, most of these studies have examined broad effects across multiple implementation sites. The purpose of the current study was to determine if such promising results could be replicated in a single rural county that has been implementing the CTC system for more than a decade. The results of this utilization-focused evaluation indicate a variety of positive effects on outcomes among adolescents
Making a Case for Engaging Adolescents in Program Decision-Making
The study discussed here examined the degree to which adolescents believe they are involved in community decision-making and examined discrepancies between adult and adolescent perceptions of common youth problems. Perceptual data were compared to adolescents\u27 self-reported behavioral data to determine if perceptions diverge from reports of actual behaviors. Results indicate that many adolescents do not believe that their thoughts are considered valuable by decision-makers. However, differences in perceptions among adults and youth suggest that adolescent perceptions should be considered. Specifically, adults were particularly aware of adolescent behaviors with observable consequences, but adolescents were more aware of internal psychological problems
Acroneuria lycorias (Boreal Stonefly, Plecoptera: Perlidae) Emergence Behaviors Discovered in Pinus strobus Canopy
Species of Plecoptera, or stoneflies, are known to use vertical emergence supports, and researchers believe many species of Plecoptera exploit arboreal habitats during emergence. However, the exact nature of these arboreal behaviors has largely remained a mystery. While exploring the habitat potential of Pinus strobus (L.) (Eastern White Pine) canopies in northern Wisconsin we observed Acroneuria lycorias (Newman) (Boreal Stonefly, Plecoptera: Perlidae) exuviae at heights as high as 12m (observations at 6.6, 9, 9.5, and 12m). Most A. lycorias exuviae appeared to have a strong preference for emergence sites at the underside or base of branches similar to some Odonate species. We also observed A. lycorias, adults climbing upwards along the main stem, post-emergence, to heights up to 22m. To our knowledge, these heights represent the greatest heights ever documented for A. lycorias adults and exuviae, or any Plecopteran species. While other researchers have speculated that A. lycorias uses arboreal habitats during emergence, these behaviors were considered almost impossible to describe. Our observations provide us with new insights into Plecopteran emergence behaviors, especially for this species. We propose three alternative hypotheses that may explain these unique emergence behaviors
Applying Coaching Strategies to Support Youth- and Family-Focused Extension Programming
In this article, we describe how a peer-coaching model has been applied to support community-based Extension programming through the Children, Youth, and Families at Risk (CYFAR) initiative. We describe the general approaches to coaching that have been used to help with CYFAR program implementation, evaluation, and sustainability efforts; we discuss strategies coaches use to maintain effective relationships with CYFAR stakeholders; and we review common characteristics of effective coaches. Finally, we discuss implications that coaching strategies might have for Extension programming in general and present future directions for research and practice related to peer coaching
A Formative Evaluation of the Children, Youth, and Families at Risk Coaching Model
In this article, we describe the results of a formative evaluation of a coaching model designed to support recipients of funding through the Children, Youth, and Families at Risk (CYFAR) initiative. Results indicate that CYFAR coaches draw from a variety of types of coaching and that CYFAR principle investigators (PIs) are generally satisfied with the coaches\u27 methods. Areas in which PIs would like to see changes to the coaching model include amount of technical coaching and amount of help with specific CYFAR funding requirements. We review strategies for incorporating this feedback into practice and discuss implications for CYFAR and for Extension in general
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