Classical and quantum communication without a shared reference frame

We show that communication without a shared reference frame is possible using entangled states. Both classical and quantum information can be communicated with perfect fidelity without a shared reference frame at a rate that asymptotically approaches one classical bit or one encoded qubit per transmitted qubit. We present an optical scheme to communicate classical bits without a shared reference frame using entangled photon pairs and linear optical Bell state measurements.Comment: 4 pages, published versio

The Red-Cockaded Woodpecker Cavity Tree: A Very Special Pine

The adaptation of red-cockaded woodpeckers (Picoides borealis) to fire-maintained southern pine ecosystems has included the development of behaviors that permit the species to use living pines for their cavity trees. Their adaptation to pine ecosystems has also involved a major adjustment in the species\u27 breeding system to cooperative breeding, probably in response to the extended time period required to excavate a completed cavity in a living pine and the relative rarity of completed cavities for nesting. The characteristics of live pines make them variable in their suitability as cavity trees, leading to the evolution of selection behavior among woodpeckers. Red-cockaded woodpeckers require a very special type of pine for their cavity tree. Potential cavity trees must be sufficiently old because only older pines have heartwood of sufficient diameter to physically house a woodpecker cavity without breaching the resin producing sapwood. Older pines also have a larger diameter of heartwood higher in the pine, permitting higher cavity placement, well away from frequent fires. Older pines also have a higher occurrence rate of red heart fungus (Phellinus pini), which decays the heartwood allowing cavity excavation to proceed more quickly. The potential cavity tree also needs to have relatively thin sapwood, which reduces the time the woodpecker must spend excavating through living xylem tissue that exudes sticky pine resin when pecked. Red-cockaded woodpeckers scale loose bark from the bole of their cavity trees and excavate resin wells above and below cavity entrances. These behaviors create a resin barrier that is very effective in deterring predation by rat snakes (Elaphe spp.). Thus, the ability of pines to produce adequate resin is also important to the woodpecker. Red-cockaded wood- peckers can detect the pine\u27s ability to produce resin and select pines that are high producers. Higher yields of resin likely create better barriers against rat snakes. The socially dominant breeding male red-cockaded woodpecker selects the cavity tree that produces the most resin for its roost tree, which during spring becomes the group\u27s nest tree. Our recent research suggests that red-cockaded woodpeckers also select pines with particular resin chemistries. High concentrations of diterpenes may increase resin viscosity, stickiness, irritability, or other factors that may be important for creating a barrier against rat snakes

Improving Pharmacy Student Communication Outcomes Using Standardized Patients

Objective. To examine whether standardized patient encounters led to an improvement in a student pharmacist-patient communication assessment compared to traditional active-learning activities within a classroom setting. Methods. A quasi-experimental study was conducted with second-year pharmacy students in a drug information and communication skills course. Student patient communication skills were assessed using high-stakes communication assessment. Results. Two hundred and twenty students’ data were included. Students were significantlymore likely to have higher scores on the communication assessment when they had higher undergraduate GPAs, were female, and taught using standardized patients. Similarly, students were significantly more likely to pass the assessment on the first attempt when they were female and when they were taught using standardized patients. Conclusion. Incorporating standardized patients within a communication course resulted in improved scores as well as first-time pass rates on a communication assessment than when using different methods of active learning

Cost-Effectiveness of Using Standardized Patients to Assess Student-Pharmacist Communication Skills

Objective. To explore the cost-effectiveness of including standardized patients (SP) in the didactic curriculum for application and assessment of students’ pharmacist-patient communication skills. Methods. Five role play/case study (RP/CS) activities from a communication skills curriculum were replaced with five SP encounters. Communication was assessed using a rubric. This study developed an economic model to examine the costs and effectiveness of replacing RP/CS events with SP events in knowledge-application and communication assessment. Costs consisted of SP hourly wages for training and delivery of SP events. Outcomes examined were the incremental cost-effectiveness ratio (ICER) per student. Results. The ICER comparing SP to RP/CS was $100.93 higher per student on first-attempt pass rates and$9.04 per one-point increase in the mean score. Conclusion. SP was more effective and more costly than RP/CS. Further research into students’ willingness to pay needs to occur before determining if using SPs is cost-effective in teaching communication skills

Dialogue Concerning Two Views on Quantum Coherence: Factist and Fictionist

A controversy that has arisen many times over in disparate contexts is whether quantum coherences between eigenstates of certain quantities are fact or fiction. We present a pedagogical introduction to the debate in the form of a hypothetical dialogue between proponents from each of the two camps: a factist and a fictionist. A resolution of the debate can be achieved, we argue, by recognizing that quantum states do not only contain information about the intrinsic properties of a system but about its extrinsic properties as well, that is, about its relation to other systems external to it. Specifically, the coherent quantum state of the factist is the appropriate description of the relation of the system to one reference frame, while the incoherent quantum state of the fictionist is the appropriate description of the relation of the system to another, uncorrelated, reference frame. The two views, we conclude, are alternative but equally valid paradigms of description.Comment: 14 pages, Contribution to the Int. J. of Quant. Info. issue dedicated to the memory of Asher Peres; v2 updated summary and critique of prior literatur

Quantum communication using a bounded-size quantum reference frame

Typical quantum communication schemes are such that to achieve perfect decoding the receiver must share a reference frame with the sender. Indeed, if the receiver only possesses a bounded-size quantum token of the sender's reference frame, then the decoding is imperfect, and we can describe this effect as a noisy quantum channel. We seek here to characterize the performance of such schemes, or equivalently, to determine the effective decoherence induced by having a bounded-size reference frame. We assume that the token is prepared in a special state that has particularly nice group-theoretic properties and that is near-optimal for transmitting information about the sender's frame. We present a decoding operation, which can be proven to be near-optimal in this case, and we demonstrate that there are two distinct ways of implementing it (corresponding to two distinct Kraus decompositions). In one, the receiver measures the orientation of the reference frame token and reorients the system appropriately. In the other, the receiver extracts the encoded information from the virtual subsystems that describe the relational degrees of freedom of the system and token. Finally, we provide explicit characterizations of these decoding schemes when the system is a single qubit and for three standard kinds of reference frame: a phase reference, a Cartesian frame (representing an orthogonal triad of spatial directions), and a reference direction (representing a single spatial direction).Comment: 17 pages, 1 figure, comments welcome; v2 published versio

Experimental and analytic studies of the triggered lightning environment of the F106B

The triggered lightning environment of the F106B aircraft is investigated. Scale modeling of the F106B with a metallized model was done to measure electric field enhancement factors on the aircraft and on canonically shaped conducting objects. These are then compared to numerically determined quantities. Detailed numerical modeling is done of the development of the triggered lightning channel. This is done using nonlinear air chemistry models to model a variety of physical phenomena which occur in a triggered lightning event. The effect of a triggered lightning strike on internal wires in the F106B is investigated using finite difference models and transmission line models to calculate the electromagnetic coupling of lightning currents through seams and joints of the aircraft to internal cables. Time domain waveforms are computed and compared to measured waveforms. The effect of thunderstorm particles on the initial triggering of a lightning strike is investigated. The electric field levels needed to cause air breakdown in the presence and absence of thunderstorm particles are calculated. This is done as a function of the size, shape, and density of the particles

Pharmacological and Toxicological Properties of the Potent Oral γ-Secretase Modulator BPN-15606.

Alzheimer's disease (AD) is characterized neuropathologically by an abundance of 1) neuritic plaques, which are primarily composed of a fibrillar 42-amino-acid amyloid-β peptide (Aβ), as well as 2) neurofibrillary tangles composed of aggregates of hyperphosporylated tau. Elevations in the concentrations of the Aβ42 peptide in the brain, as a result of either increased production or decreased clearance, are postulated to initiate and drive the AD pathologic process. We initially introduced a novel class of bridged aromatics referred tγ-secretase modulatoro as γ-secretase modulators that inhibited the production of the Aβ42 peptide and to a lesser degree the Aβ40 peptide while concomitantly increasing the production of the carboxyl-truncated Aβ38 and Aβ37 peptides. These modulators potently lower Aβ42 levels without inhibiting the γ-secretase-mediated proteolysis of Notch or causing accumulation of carboxyl-terminal fragments of APP. In this study, we report a large number of pharmacological studies and early assessment of toxicology characterizing a highly potent γ-secretase modulator (GSM), (S)-N-(1-(4-fluorophenyl)ethyl)-6-(6-methoxy-5-(4-methyl-1H-imidazol-1-yl)pyridin-2-yl)-4-methylpyridazin-3-amine (BPN-15606). BPN-15606 displayed the ability to significantly lower Aβ42 levels in the central nervous system of rats and mice at doses as low as 5-10 mg/kg, significantly reduce Aβ neuritic plaque load in an AD transgenic mouse model, and significantly reduce levels of insoluble Aβ42 and pThr181 tau in a three-dimensional human neural cell culture model. Results from repeat-dose toxicity studies in rats and dose escalation/repeat-dose toxicity studies in nonhuman primates have designated this GSM for 28-day Investigational New Drug-enabling good laboratory practice studies and positioned it as a candidate for human clinical trials

Reference frames, superselection rules, and quantum information

Recently, there has been much interest in a new kind of ``unspeakable'' quantum information that stands to regular quantum information in the same way that a direction in space or a moment in time stands to a classical bit string: the former can only be encoded using particular degrees of freedom while the latter are indifferent to the physical nature of the information carriers. The problem of correlating distant reference frames, of which aligning Cartesian axes and synchronizing clocks are important instances, is an example of a task that requires the exchange of unspeakable information and for which it is interesting to determine the fundamental quantum limit of efficiency. There have also been many investigations into the information theory that is appropriate for parties that lack reference frames or that lack correlation between their reference frames, restrictions that result in global and local superselection rules. In the presence of these, quantum unspeakable information becomes a new kind of resource that can be manipulated, depleted, quantified, etcetera. Methods have also been developed to contend with these restrictions using relational encodings, particularly in the context of computation, cryptography, communication, and the manipulation of entanglement. This article reviews the role of reference frames and superselection rules in the theory of quantum information processing.Comment: 55 pages, published versio