Prevalence, Reasons for Use, and Risk Perception of Electronic Cigarettes among Post-Acute Coronary Syndrome Smokers

Purpose—The use of electronic cigarettes (e-cigarettes) has risen dramatically in recent years. However, there is currently no published data on use of e-cigarettes among cardiac patients. The current study reports on the prevalence, reasons for use, and perceived risks of e-cigarettes among post-Acute Coronary Syndrome (ACS) patients. The relationship between e-cigarette use and post- ACS tobacco smoking cessation is also explored. Methods—Participants were drawn from a randomized trial of smoking cessation treatments following hospitalization for ACS. The current study focuses on 49 participants that completed e- cigarette questions at 24 weeks post-ACS. Results—51.0% of participants reported ever use of an e-cigarette and 26.5% reported using an e-cigarette at some time during the 24 weeks post-ACS. Ever use and post-ACS use were both significantly associated with lower rates of abstinence from tobacco cigarettes. Participants perceived e-cigarettes as less harmful to cardiac health than tobacco use and Chantix, and similarly harmful as nicotine replacement therapy. Participant perceived likelihood of experiencing a heart attack in the next year was 34.6% if they were to regularly use e-cigarettes only, significantly lower than perceived risk of recurrence if they were to regularly smoke only tobacco cigarettes (56.2%) and significantly higher than perceived risk of recurrence if they were to use no nicotine (15.2%). Conclusions—A significant minority of patients are using e-cigarettes post-ACS. Providers should be prepared to discuss potential discrepancies between patient beliefs about the safety of e- cigarettes and the current state of the science

Localized quantum walks as secured quantum memory

We show that a quantum walk process can be used to construct and secure quantum memory. More precisely, we show that a localized quantum walk with temporal disorder can be engineered to store the information of a single, unknown qubit on a compact position space and faithfully recover it on demand. Since the localization occurss with a finite spread in position space, the stored information of the qubit will be naturally secured from the simple eavesdropper. Our protocol can be adopted to any quantum system for which experimental control over quantum walk dynamics can be achieved.Comment: 7 pages, 4 figure

Assembly Bias and Splashback in Galaxy Clusters

We use publicly available data for the Millennium Simulation to explore the implications of the recent detection of assembly bias and splashback signatures in a large sample of galaxy clusters. These were identified in the SDSS/DR8 photometric data by the redMaPPer algorithm and split into high- and low-concentration subsamples based on the projected positions of cluster members. We use simplified versions of these procedures to build cluster samples of similar size from the simulation data. These match the observed samples quite well and show similar assembly bias and splashback signals. Previous theoretical work has found the logarithmic slope of halo density profiles to have a well-defined minimum whose depth decreases and whose radius increases with halo concentration. Projected profiles for the observed and simulated cluster samples show trends with concentration which are opposite to these predictions. In addition, for high-concentration clusters the minimum slope occurs at significantly smaller radius than predicted. We show that these discrepancies all reflect confusion between splashback features and features imposed on the profiles by the cluster identification and concentration estimation procedures. The strong apparent assembly bias is not reflected in the three-dimensional distribution of matter around clusters. Rather it is a consequence of the preferential contamination of low-concentration clusters by foreground or background groups.Comment: 17 pages, 16 figures, 3 tables, accepted versio

The Yagita invariant of symplectic groups of large rank

Fix a prime $p$, and let $R$ be any subring of the complex numbers that is either integrally closed or contains a primitive $p$th root of 1. For each $n\geq p-1$ we compute the Yagita invariant at the prime $p$ for the symplectic group $Sp(2n,R)$.Comment: Minor changes compared to first versio

Behavioral activation for smoking cessation and mood management following a cardiac event: results of a pilot randomized controlled trial

Background: Smoking cessation following hospitalization for Acute Coronary Syndrome (ACS) significantly reduces subsequent mortality. Depressed mood is a major barrier to cessation post-ACS. Although existing counseling treatments address smoking and depression independently in ACS patients, no integrated treatment addresses both. We developed an integrated treatment combining gold standard cessation counseling with behavioral activation-based mood management; Behavioral Activation Treatment for Cardiac Smokers (BAT-CS). The purpose of this pilot randomized controlled trial was to test feasibility, acceptability, and preliminary efficacy of BAT-CS vs. Standard of Care (SC). Methods: Participants were recruited during hospitalization for ACS and were randomly assigned to BAT-CS or SC. The nicotine patch was offered in both conditions. Smoking, mood, and stress outcomes were collected at end-of-treatment and 24-week follow-up. Results: Fifty-nine participants (28 BAT-CS, 31 SC) were recruited over 42 weeks, and assessment completion was above 80% in both conditions. Treatment acceptability and fidelity were high. At 24 week follow-up adjusted odds ratios favoring BAT-CS were 1.27 (95% CI: 0.41–3.93) for 7-day point prevalence abstinence and 1.27 (95% CI: 0.42–3.82) for continuous abstinence. Time to first smoking lapse was significantly longer in BAT-CS (62.4 vs. 31.8 days, p = 0.03). At 24-weeks, effect sizes for mood and stress outcomes ranged from η2 of.07–.11, with significant between treatment effects for positive affect, negative affect, and stress. Conclusions: The design of this study proved feasible and acceptable. Results provide preliminary evidence that combining behavioral activation with standard smoking cessation counseling could be efficacious for this high risk population. A larger trial with longer follow-up is warranted. Trial registration: NCT01964898. First received by clinicaltrials.gov October 15, 2013

Non-disturbing quantum measurements

We consider pairs of quantum observables (POVMs) and analyze the relation between the notions of non-disturbance, joint measurability and commutativity. We specify conditions under which these properties coincide or differ---depending for instance on the interplay between the number of outcomes and the Hilbert space dimension or on algebraic properties of the effect operators. We also show that (non-)disturbance is in general not a symmetric relation and that it can be decided and quantified by means of a semidefinite program.Comment: Minor corrections in v

Characterization of the Sequential Product on Quantum Effects

We present a characterization of the standard sequential product of quantum effects. The characterization is in term of algebraic, continuity and duality conditions that can be physically motivated.Comment: 11 pages. Accepted for publication in the Journal of Mathematical Physic

The Standard Model of Quantum Measurement Theory: History and Applications

The standard model of the quantum theory of measurement is based on an interaction Hamiltonian in which the observable-to-be-measured is multiplied with some observable of a probe system. This simple Ansatz has proved extremely fruitful in the development of the foundations of quantum mechanics. While the ensuing type of models has often been argued to be rather artificial, recent advances in quantum optics have demonstrated their prinicpal and practical feasibility. A brief historical review of the standard model together with an outline of its virtues and limitations are presented as an illustration of the mutual inspiration that has always taken place between foundational and experimental research in quantum physics.Comment: 22 pages, to appear in Found. Phys. 199